286 results on '"Daniel R. Gamelin"'
Search Results
2. Photoconductive ZnO films with embedded quantum dot or ruthenium dye sensitizers
- Author
-
Michael A. White, Jillian L. Dempsey, Gerard M. Carroll, James D. Gallagher, and Daniel R. Gamelin
- Subjects
Biotechnology ,TP248.13-248.65 ,Physics ,QC1-999 - Abstract
We report a new type of solution-processed photoconductive film based on embedding photosensitizers (semiconductor nanocrystals or ruthenium dye molecules) within conductive ZnO sol-gel matrices. Mixing photosensitizers directly with sol-gel precursors prior to film deposition yields highly colored ZnO films containing well-dispersed sensitizers. These films show internal photoconductivity quantum efficiencies up to ∼50% and photoresponses over 100 mA/W with visible photoexcitation, competitive with other more complex photodetectors reported recently. This simple motif is attractive for the development of robust sensitized-oxide photodetectors and for fundamental studies of photoinduced charge separation from a variety of molecular or quantum dot sensitizers into conductive oxides.
- Published
- 2013
- Full Text
- View/download PDF
3. Intercell moiré exciton complexes in electron lattices
- Author
-
Xi Wang, Xiaowei Zhang, Jiayi Zhu, Heonjoon Park, Yingqi Wang, Chong Wang, William G. Holtzmann, Takashi Taniguchi, Kenji Watanabe, Jiaqiang Yan, Daniel R. Gamelin, Wang Yao, Di Xiao, Ting Cao, and Xiaodong Xu
- Subjects
Condensed Matter::Quantum Gases ,Condensed Matter::Materials Science ,Condensed Matter - Mesoscale and Nanoscale Physics ,Condensed Matter::Other ,Mechanics of Materials ,Mechanical Engineering ,Mesoscale and Nanoscale Physics (cond-mat.mes-hall) ,FOS: Physical sciences ,General Materials Science ,General Chemistry ,Condensed Matter::Mesoscopic Systems and Quantum Hall Effect ,Condensed Matter Physics - Abstract
Excitons, Coulomb-bound electron-hole pairs, play a fundamental role in both optical excitation and correlated phenomena in solids. When an exciton interacts with other quasi-particles, few- and many-body excited states, such as trions, exciton Fermi-polarons, Mahan excitons can appear. Here, we report a new interaction between exciton and charges enabled by unusual quantum confinement in 2D moir\'e superlattices, which results in novel exciton many-body ground states composed of moir\'e excitons and correlated electron lattices. Unique to H-stacked (or 60o-twisted) WS2/WSe2 heterobilayer, we found that the interlayer atomic registry and moir\'e structural reconstruction leads to an interlayer moir\'e exciton (IME) whose hole in one layer is surrounded by its partner electron's wavefunction spread among three adjacent moir\'e traps in the other layer. This 3D excitonic structure can enable large in-plane electrical quadrupole moments in addition to the vertical dipole. Upon doping, the electric quadrupole facilitates the binding of IME to the charges in neighboring moir\'e cells, forming an intercell charged exciton complex. The exciton complex is unveiled by the IME photoluminescence energy jumps when the electron lattices form at both fractional and integer-filled moir\'e minibands, with replica-like spectral features between successive integer moir\'e fillings. Our work provides the framework in understanding and engineering emergent exciton many-body states in correlated moir\'e charge orders.
- Published
- 2023
4. HF-Free synthesis of colloidal Cs2ZrF6 and (NH4)2ZrF6 nanocrystals
- Author
-
Eden Tzanetopoulos, Julie Schwartz, and Daniel R. Gamelin
- Subjects
Materials Chemistry ,Metals and Alloys ,Ceramics and Composites ,General Chemistry ,Catalysis ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials - Abstract
Syntheses of colloidal Cs2ZrF6 and (NH4)2ZrF6 nanocrystals have been developed that use NH4F dissolved in a low-boiling-point alcohol as a reactive fluoride source, demonstrating the first A2BF6 nanocrystals prepared without the need to handle HF.
- Published
- 2023
5. Universal machine learning framework for defect predictions in zinc blende semiconductors.
- Author
-
Arun Mannodi-Kanakkithodi, Xiaofeng Xiang, Laura Jacoby, Robert Biegaj, Scott T. Dunham, Daniel R. Gamelin, and Maria K. Y. Chan
- Published
- 2022
- Full Text
- View/download PDF
6. Synthetic Control of Intrinsic Defect Formation in Metal Oxide Nanocrystals Using Dissociated Spectator Metal Salts
- Author
-
Kihoon Kim, Jiwon Yu, Jungchul Noh, Lauren C. Reimnitz, Matthew Chang, Daniel R. Gamelin, Brian A. Korgel, Gyeong S. Hwang, and Delia J. Milliron
- Subjects
Colloid and Surface Chemistry ,General Chemistry ,Biochemistry ,Catalysis - Abstract
Crystallographic defects are essential to the functional properties of semiconductors, controlling everything from conductivity to optical properties and catalytic activity. In nanocrystals, too, defect engineering with extrinsic dopants has been fruitful. Although intrinsic defects like vacancies can be equally useful, synthetic strategies for controlling their generation are comparatively underdeveloped. Here, we show that intrinsic defect concentration can be tuned during the synthesis of colloidal metal oxide nanocrystals by the addition of metal salts. Although not incorporated in the nanocrystals, the metal salts dissociate at high temperatures, promoting the dissociation of carboxylate ligands from metal precursors, leading to the introduction of oxygen vacancies. For example, the concentration of oxygen vacancies can be controlled up to 9% in indium oxide nanocrystals. This method is broadly applicable as we demonstrate by generating intrinsic defects in metal oxide nanocrystals of various morphologies and compositions.
- Published
- 2022
7. Understanding External Pressure Effects and Interlayer Orbital Exchange Pathways in the Two-Dimensional Magnet─Chromium Triiodide
- Author
-
Ryan A. Beck, Shichao Sun, Xiaodong Xu, Daniel R. Gamelin, Ting Cao, and Xiaosong Li
- Subjects
General Energy ,Physical and Theoretical Chemistry ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials - Published
- 2022
8. Effect of a redox-mediating ligand shell on photocatalysis by CdS quantum dots
- Author
-
Florence Y. Dou, Samantha M. Harvey, Konstantina G. Mason, Micaela K. Homer, Daniel R. Gamelin, and Brandi M. Cossairt
- Subjects
General Physics and Astronomy ,Physical and Theoretical Chemistry - Abstract
Semiconductor quantum dots (QDs) are efficient organic photoredox catalysts due to their high extinction coefficients and easily tunable band edge potentials. Despite the majority of the surface being covered by ligands, our understanding of the effect of the ligand shell on organic photocatalysis is limited to steric effects. We hypothesize that we can increase the activity of QD photocatalysts by designing a ligand shell with targeted electronic properties, namely, redox-mediating ligands. Herein, we functionalize our QDs with hole-mediating ferrocene (Fc) derivative ligands and perform a reaction where the slow step is hole transfer from QD to substrate. Surprisingly, we find that a hole-shuttling Fc inhibits catalysis, but confers much greater stability to the catalyst by preventing a build-up of destructive holes. We also find that dynamically bound Fc ligands can promote catalysis by surface exchange and creation of a more permeable ligand shell. Finally, we find that trapping the electron on a ligand dramatically increases the rate of reaction. These results have major implications for understanding the rate-limiting processes for charge transfer from QDs and the role of the ligand shell in modulating it.
- Published
- 2023
9. Light-induced ferromagnetism in moiré superlattices
- Author
-
Xi Wang, Chengxin Xiao, Heonjoon Park, Jiayi Zhu, Chong Wang, Takashi Taniguchi, Kenji Watanabe, Jiaqiang Yan, Di Xiao, Daniel R. Gamelin, Wang Yao, and Xiaodong Xu
- Subjects
Condensed Matter::Materials Science ,Multidisciplinary ,Condensed Matter - Mesoscale and Nanoscale Physics ,Mesoscale and Nanoscale Physics (cond-mat.mes-hall) ,FOS: Physical sciences - Abstract
Many-body interactions between carriers lie at the heart of correlated physics. The ability to tune such interactions would open the possibility to access and control complex electronic phase diagrams on demand. Recently, moir\'e superlattices formed by two-dimensional materials have emerged as a promising platform for quantum engineering such phenomena. The power of the moir\'e system lies in the high tunability of its physical parameters by tweaking layer twist angle, electrical field, moir\'e carrier filling, and interlayer coupling. Here, we report that optical excitation can drastically tune the spin-spin interactions between moir\'e trapped carriers, resulting in ferromagnetic order in WS2/WSe2 moir\'e superlattices over a small range of doping at elevated temperatures. Near the filling factor v = -1/3 (i.e., one hole per three moir\'e unit cells), as the excitation power at the exciton resonance increases, a well-developed hysteresis loop emerges in the reflective magnetic circular dichroism (RMCD) signal as a function of magnetic field, a hallmark of ferromagnetism. The hysteresis loop persists down to charge neutrality, and its shape evolves as the moir\'e superlattice is gradually filled, indicating changes of magnetic ground state properties. The observed phenomenon points to a mechanism in which itinerant photo-excited excitons mediate exchange coupling between moir\'e trapped holes. This exciton-mediated interaction can be of longer range than direct coupling between moir\'e trapped holes, and thus magnetic order can arise even in the dilute hole regime under optical excitation. This discovery adds a new and dynamic tuning knob to the rich many-body Hamiltonian of moir\'e quantum matter.
- Published
- 2022
10. Ubiquitous Near-Band-Edge Defect State in Rare-Earth-Doped Lead-Halide Perovskites
- Author
-
Tyler J. Milstein, Joo Yeon D. Roh, Laura M. Jacoby, Matthew J. Crane, David E. Sommer, Scott T. Dunham, and Daniel R. Gamelin
- Subjects
General Chemical Engineering ,Materials Chemistry ,General Chemistry - Published
- 2022
11. Magnetic Amplification at Yb3+ 'Designer Defects' in the van der Waals Ferromagnet, CrI3
- Author
-
Kimo Pressler, Thom J. Snoeren, Kelly M. Walsh, and Daniel R. Gamelin
- Subjects
Condensed Matter - Materials Science ,Condensed Matter - Strongly Correlated Electrons ,Strongly Correlated Electrons (cond-mat.str-el) ,Mechanical Engineering ,Materials Science (cond-mat.mtrl-sci) ,FOS: Physical sciences ,General Materials Science ,Bioengineering ,General Chemistry ,Condensed Matter Physics - Abstract
The two-dimensional (2D) van der Waals ferromagnet CrI3 has been doped with the magnetic optical impurity Yb3+ to yield materials that display sharp multi-line Yb3+ photoluminescence (PL) controlled by the magnetism of CrI3. Magneto-PL shows that Yb3+ magnetization is pinned to the magnetization of CrI3. An effective internal field of ~10 T at Yb3+ is estimated, attributed to strong in-plane Yb3+-Cr3+ superexchange coupling. The anomalously low energy of Yb3+ PL in CrI3 reflects relatively high Yb3+-I- covalency, contributing to Yb3+-Cr3+ superexchange coupling. The Yb3+ PL energy and linewidth both reveal the effects of spontaneous zero-field CrI3 magnetic ordering within 2D layers below TC, despite the absence of net magnetization in multilayer samples. These results illustrate the use of optical impurities as "designer defects" to introduce unique functionality to 2D magnets., Comment: submitted to Nano Letters
- Published
- 2023
- Full Text
- View/download PDF
12. Coherent Spin Dynamics in Vapor-Deposited CsPbBr3 Perovskite Thin Films
- Author
-
Laura M. Jacoby, Matthew J. Crane, and Daniel R. Gamelin
- Subjects
General Chemical Engineering ,Materials Chemistry ,General Chemistry - Published
- 2022
13. Uncovering the Influence of Ni2+ Doping in Lead-Halide Perovskite Nanocrystals Using Optically Detected Magnetic Resonance Spectroscopy
- Author
-
Yahel Barak, Itay Meir, Joanna Dehnel, Faris Horani, Daniel R. Gamelin, Arthur Shapiro, and Efrat Lifshitz
- Subjects
General Chemical Engineering ,Materials Chemistry ,General Chemistry - Published
- 2022
14. Ferromagnetism and Spin-Polarized Luminescence in Lead-Free CsEuCl3 Perovskite Nanocrystals and Thin Films
- Author
-
Kelly M. Walsh, Kimo Pressler, Matthew J. Crane, and Daniel R. Gamelin
- Subjects
General Engineering ,General Physics and Astronomy ,General Materials Science - Published
- 2022
15. Organic building blocks at inorganic nanomaterial interfaces
- Author
-
Hao A Nguyen, Florence Y. Dou, Laura M. Jacoby, Yunping Huang, Daniel R. Gamelin, Helen Larson, Theodore A. Cohen, Breena M. Sperry, Micaela K Homer, Christine K. Luscombe, and Brandi M. Cossairt
- Subjects
Silicon ,Materials science ,chemistry.chemical_element ,Nanotechnology ,02 engineering and technology ,010402 general chemistry ,01 natural sciences ,Nanomaterials ,Photovoltaics ,General Materials Science ,Electrical and Electronic Engineering ,business.industry ,Process Chemistry and Technology ,Lasers ,021001 nanoscience & nanotechnology ,0104 chemical sciences ,Nanostructures ,Semiconductor ,chemistry ,Semiconductors ,Mechanics of Materials ,Photocatalysis ,Surface modification ,Photonics ,0210 nano-technology ,business ,Carbon - Abstract
This tutorial review presents our perspective on designing organic molecules for the functionalization of inorganic nanomaterial surfaces, through the model of an "anchor-functionality" paradigm. This "anchor-functionality" paradigm is a streamlined design strategy developed from a comprehensive range of materials (e.g., lead halide perovskites, II-VI semiconductors, III-V semiconductors, metal oxides, diamonds, carbon dots, silicon, etc.) and applications (e.g., light-emitting diodes, photovoltaics, lasers, photonic cavities, photocatalysis, fluorescence imaging, photo dynamic therapy, drug delivery, etc.). The structure of this organic interface modifier comprises two key components: anchor groups binding to inorganic surfaces and functional groups that optimize their performance in specific applications. To help readers better understand and utilize this approach, the roles of different anchor groups and different functional groups are discussed and explained through their interactions with inorganic materials and external environments.
- Published
- 2022
16. Moiré trions in MoSe2/WSe2 heterobilayers
- Author
-
Pasqual Rivera, Wang Yao, Xi Wang, Jiaqiang Yan, Minhao He, Takashi Taniguchi, Yingqi Wang, Kenji Watanabe, Daniel R. Gamelin, Huiyuan Zheng, David Mandrus, Kyle L. Seyler, Xiaodong Xu, and Jiayi Zhu
- Subjects
Condensed Matter::Quantum Gases ,Physics ,Photoluminescence ,Condensed matter physics ,Exciton ,Relaxation (NMR) ,Biomedical Engineering ,Charge number ,Bioengineering ,Electron ,Condensed Matter::Mesoscopic Systems and Quantum Hall Effect ,Condensed Matter Physics ,Polarization (waves) ,Atomic and Molecular Physics, and Optics ,Condensed Matter::Materials Science ,Coulomb ,General Materials Science ,Electrical and Electronic Engineering ,Trion - Abstract
Transition metal dichalcogenide moire bilayers with spatially periodic potentials have emerged as a highly tunable platform for studying both electronic1–6 and excitonic4,7–13 phenomena. The power of these systems lies in the combination of strong Coulomb interactions with the capability of controlling the charge number in a moire potential trap. Electronically, exotic charge orders at both integer and fractional fillings have been discovered2,5. However, the impact of charging effects on excitons trapped in moire potentials is poorly understood. Here, we report the observation of moire trions and their doping-dependent photoluminescence polarization in H-stacked MoSe2/WSe2 heterobilayers. We find that as moire traps are filled with either electrons or holes, new sets of interlayer exciton photoluminescence peaks with narrow linewidths emerge about 7 meV below the energy of the neutral moire excitons. Circularly polarized photoluminescence reveals switching from co-circular to cross-circular polarizations as moire excitons go from being negatively charged and neutral to positively charged. This switching results from the competition between valley-flip and spin-flip energy relaxation pathways of photo-excited electrons during interlayer trion formation. Our results offer a starting point for engineering both bosonic and fermionic many-body effects based on moire excitons14. Moire trions are observed in electrostatically gated WSe2/MoSe2 heterobilayers, where photoluminescence polarization switching reveals a competition between valley-flip and spin-flip relaxation pathways of photo-excited carriers during trion formation.
- Published
- 2021
17. Tunable Band-Edge Potentials and Charge Storage in Colloidal Tin-Doped Indium Oxide (ITO) Nanocrystals
- Author
-
Hongbin Liu, Jose J. Araujo, Daniel R. Gamelin, Anna Merkulova, Carl K. Brozek, and Xiaosong Li
- Subjects
Materials science ,Dopant ,Fermi level ,Doping ,General Engineering ,General Physics and Astronomy ,chemistry.chemical_element ,Delocalized electron ,symbols.namesake ,chemistry ,Chemical physics ,symbols ,General Materials Science ,Charge carrier ,Surface charge ,Indium ,Localized surface plasmon - Abstract
Degenerately doped metal-oxide nanocrystals (NCs) show localized surface plasmon resonances (LSPRs) that are tunable via their tunable excess charge-carrier densities. Modulation of excess charge carriers has also been used to control magnetism in colloidal doped metal-oxide NCs. The addition of excess delocalized conduction-band (CB) electrons can be achieved through aliovalent doping or by postsynthetic techniques such as electrochemistry or photodoping. Here, we examine the influence of charge-compensating aliovalent dopants on the potentials of excess CB electrons in free-standing colloidal degenerately doped oxide NCs, both experimentally and through modeling. Taking Sn4+:In2O3 (ITO) NCs as a model system, we use spectroelectrochemical techniques to examine differences between aliovalent doping and photodoping. We demonstrate that whereas photodoping introduces excess CB electrons by raising the Fermi level relative to the CB edge, aliovalent impurity substitution introduces excess CB electrons by stabilizing the CB edge relative to an externally defined Fermi level. Significant differences are thus observed electrochemically between spectroscopically similar delocalized CB electrons compensated by aliovalent dopants and those compensated by surface cations (e.g., protons) during photodoping. Theoretical modeling illustrates the very different potentials that arise from charge compensation via aliovalent substitution and surface charge compensation. Spectroelectrochemical titrations allow the ITO NC band-edge stabilization as a function of Sn4+ doping to be quantified. Extremely large capacitances are observed in both In2O3 and ITO NCs, making these NCs attractive for reversible charge-storage applications.
- Published
- 2021
18. Orientation of Individual Anisotropic Nanocrystals Identified by Polarization Fingerprint
- Author
-
Severin Lorenz, Jan Bieniek, Gerd Bacher, Daniel R. Gamelin, Christian S. Erickson, and Rachel Fainblat
- Subjects
Materials science ,Condensed matter physics ,Linear polarization ,General Engineering ,Physics::Optics ,General Physics and Astronomy ,Condensed Matter::Mesoscopic Systems and Quantum Hall Effect ,Polarization (waves) ,Optical axis ,Condensed Matter::Materials Science ,symbols.namesake ,Nanocrystal ,Quantum dot ,symbols ,Stokes parameters ,General Materials Science ,Anisotropy ,Elektrotechnik ,Wurtzite crystal structure - Abstract
The polarization of photoluminescence emitted from anisotropic nanocrystals directly reflects the symmetry of the eigenstates involved in the recombination process and can thus be considered as a characteristic feature of a nanocrystal. We performed polarization resolved magneto-photoluminescence spectroscopy on single colloidal Mn2+:CdSe/CdS core-shell quantum dots of wurtzite crystal symmetry. At zero magnetic field, a distinct linear polarization pattern is observed, while applying a magnetic field enforces circularly polarized emission with a characteristic saturation value below 100%. These polarization features are shown to act as a specific fingerprint of each individual nanocrystal. A model considering the orientation of the crystal c axis with respect to the optical axis and the magnetic field and taking into account the impact of magnetic doping is introduced and quantitatively explains our findings. We demonstrate that a careful analysis of the polarization state of single nanocrystal emission using the full set of Stokes parameters allows for identification of the complete three-dimensional orientation of the crystal anisotropy axis of an individual nanoobject in lab coordinates.
- Published
- 2021
19. Optically Detected Magnetic Resonance Spectroscopy of Cu-Doped CdSe/CdS and CuInS
- Author
-
Adi, Harchol, Yahel, Barak, Kira E, Hughes, Kimberly H, Hartstein, Huygen J, Jöbsis, P Tim, Prins, Celso, de Mello Donegá, Daniel R, Gamelin, and Efrat, Lifshitz
- Abstract
Copper-doped II-VI and copper-based I-III-VI
- Published
- 2022
20. Defect structure in quantum-cutting Yb3+ -doped CsPbCl3 perovskites probed by x-ray absorption and atomic pair distribution function analysis
- Author
-
Kyle T. Kluherz, Sebastian T. Mergelsberg, David E. Sommer, Joo Yeon D. Roh, Sarah A. Saslow, Daniel Biner, Karl W. Krämer, Scott T. Dunham, James J. De Yoreo, and Daniel R. Gamelin
- Subjects
Physics and Astronomy (miscellaneous) ,General Materials Science - Published
- 2022
21. Direct Patterning of Perovskite Nanocrystals on Nanophotonic Cavities with Electrohydrodynamic Inkjet Printing
- Author
-
Theodore A. Cohen, David Sharp, Kyle T. Kluherz, Yueyang Chen, Christopher Munley, Rayne T. Anderson, Connor J. Swanson, James J. De Yoreo, Christine K. Luscombe, Arka Majumdar, Daniel R. Gamelin, and J. Devin Mackenzie
- Subjects
Mechanical Engineering ,General Materials Science ,Bioengineering ,General Chemistry ,Condensed Matter Physics - Abstract
Overcoming the challenges of patterning luminescent materials will unlock additive and more sustainable paths for the manufacturing of next-generation on-chip photonic devices. Electrohydrodynamic (EHD) inkjet printing is a promising method for deterministically placing emitters on these photonic devices. However, the use of this technique to pattern luminescent lead halide perovskite nanocrystals (NCs), notable for their defect tolerance and impressive optical and spin coherence properties, for integration with optoelectronic devices remains unexplored. In this work, we additively deposit nanoscale CsPbBr
- Published
- 2022
22. Modular Zwitterion-Functionalized Poly(isopropyl methacrylate) Polymers for Hosting Luminescent Lead Halide Perovskite Nanocrystals
- Author
-
Connor S. Juhl, Christine K. Luscombe, Yunping Huang, Nico A. Bricker, Theodore A. Cohen, Tyler J. Milstein, Daniel R. Gamelin, and J. Devin MacKenzie
- Subjects
Materials science ,General Chemical Engineering ,Halide ,02 engineering and technology ,General Chemistry ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Photochemistry ,01 natural sciences ,0104 chemical sciences ,Methacrylate polymers ,chemistry.chemical_compound ,Nanocrystal ,chemistry ,Zwitterion ,Materials Chemistry ,0210 nano-technology ,Luminescence ,Inorganic lead ,Isopropyl ,Perovskite (structure) - Abstract
Inorganic lead halide perovskite nanocrystals (NCs) are an exciting class of luminescent materials with high defect tolerance and broad spectral tunability, but such NCs are vulnerable to degradati...
- Published
- 2021
23. Highly luminescent and catalytically active suprastructures of magic-sized semiconductor nanoclusters
- Author
-
Megalamane S. Bootharaju, Kelly M. Walsh, Sanghwa Lee, Woonhyuk Baek, Taeghwan Hyeon, and Daniel R. Gamelin
- Subjects
Photoluminescence ,Materials science ,Chalcogenide ,Mechanical Engineering ,02 engineering and technology ,General Chemistry ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,01 natural sciences ,0104 chemical sciences ,Catalysis ,Turnover number ,Nanoclusters ,Metal ,chemistry.chemical_compound ,chemistry ,Chemical engineering ,Mechanics of Materials ,Diamine ,visual_art ,visual_art.visual_art_medium ,General Materials Science ,0210 nano-technology ,Luminescence - Abstract
Metal chalcogenide magic-sized nanoclusters have shown intriguing photophysical and chemical properties, yet ambient instability has hampered their extensive applications. Here we explore the periodic assembly of these nanoscale building blocks through organic linkers to overcome such limitations and further boost their properties. We designed a diamine-based heat-up self-assembly process to assemble Mn2+:(CdSe)13 and Mn2+:(ZnSe)13 magic-sized nanoclusters into three- and two-dimensional suprastructures, respectively, obtaining enhanced stability and solid-state photoluminescence quantum yields (from
- Published
- 2021
24. Defect formation in Yb-doped CsPbCl3 from first principles with implications for quantum cutting
- Author
-
David E. Sommer, Daniel R. Gamelin, and Scott T. Dunham
- Subjects
Physics and Astronomy (miscellaneous) ,General Materials Science - Published
- 2022
25. Consensus statement: Standardized reporting of power-producing luminescent solar concentrator performance
- Author
-
Chenchen Yang, Harry A. Atwater, Marc A. Baldo, Derya Baran, Christopher J. Barile, Miles C. Barr, Matthew Bates, Moungi G. Bawendi, Matthew R. Bergren, Babak Borhan, Christoph J. Brabec, Sergio Brovelli, Vladimir Bulović, Paola Ceroni, Michael G. Debije, Jose-Maria Delgado-Sanchez, Wen-Ji Dong, Phillip M. Duxbury, Rachel C. Evans, Stephen R. Forrest, Daniel R. Gamelin, Noel C. Giebink, Xiao Gong, Gianmarco Griffini, Fei Guo, Christopher K. Herrera, Anita W.Y. Ho-Baillie, Russell J. Holmes, Sung-Kyu Hong, Thomas Kirchartz, Benjamin G. Levine, Hongbo Li, Yilin Li, Dianyi Liu, Maria A. Loi, Christine K. Luscombe, Nikolay S. Makarov, Fahad Mateen, Raffaello Mazzaro, Hunter McDaniel, Michael D. McGehee, Francesco Meinardi, Amador Menéndez-Velázquez, Jie Min, David B. Mitzi, Mehdi Moemeni, Jun Hyuk Moon, Andrew Nattestad, Mohammad K. Nazeeruddin, Ana F. Nogueira, Ulrich W. Paetzold, David L. Patrick, Andrea Pucci, Barry P. Rand, Elsa Reichmanis, Bryce S. Richards, Jean Roncali, Federico Rosei, Timothy W. Schmidt, Franky So, Chang-Ching Tu, Aria Vahdani, Wilfried G.J.H.M. van Sark, Rafael Verduzco, Alberto Vomiero, Wallace W.H. Wong, Kaifeng Wu, Hin-Lap Yip, Xiaowei Zhang, Haiguang Zhao, Richard R. Lunt, Evans, Rachel [0000-0003-2956-4857], Apollo - University of Cambridge Repository, Integration of Photovoltaic Solar Energy, Energy and Resources, Stimuli-responsive Funct. Materials & Dev., ICMS Core, EIRES Chem. for Sustainable Energy Systems, EIRES System Integration, Yang, CC, Atwater, HA, Baldo, MA, Baran, D, Barile, CJ, Barr, MC, Bates, M, Bawendi, MG, Bergren, MR, Borhan, B, Brabec, CJ, Brovelli, S, Bulovic, V, Ceroni, P, Debije, MG, Delgado-Sanchez, JM, Dong, WJ, Duxbury, PM, Evans, RC, Forrest, SR, Gamelin, DR, Giebink, NC, Gong, X, Griffini, G, Guo, F, Herrera, CK, Ho-Baillie, AWY, Holmes, RJ, Hong, SK, Kirchartz, T, Levine, BG, Li, HB, Li, YL, Liu, DY, Loi, MA, Luscombe, CK, Makarov, NS, Mateen, F, Mazzaro, R, McDaniel, H, McGehee, MD, Meinardi, F, Menendez-Velazquez, A, Min, J, Mitzi, DB, Moemeni, M, Moon, JH, Nattestad, A, Nazeeruddin, MK, Nogueira, AF, Paetzold, UW, Patrick, DL, Pucci, A, Rand, BP, Reichmanis, E, Richards, BS, Roncali, J, Rosei, F, Schmidt, TW, So, F, Tu, CC, Vahdani, A, van Sark, WGJHM, Verduzco, R, Vomiero, A, Wong, WWH, Wu, KF, Yip, HL, Zhang, XW, Zhao, HG, Lunt, RR, Yang, C, Atwater, H, Baldo, M, Barile, C, Barr, M, Bawendi, M, Bergren, M, Brabec, C, Bulović, V, Debije, M, Delgado-Sanchez, J, Dong, W, Duxbury, P, Evans, R, Forrest, S, Gamelin, D, Giebink, N, Herrera, C, Ho-Baillie, A, Holmes, R, Hong, S, Levine, B, Li, H, Li, Y, Liu, D, Loi, M, Luscombe, C, Makarov, N, Mcdaniel, H, Mcgehee, M, Menéndez-Velázquez, A, Mitzi, D, Moon, J, Nazeeruddin, M, Nogueira, A, Paetzold, U, Patrick, D, Rand, B, Richards, B, Schmidt, T, Tu, C, van Sark, W, Wong, W, Wu, K, Yip, H, Zhang, X, Zhao, H, and Lunt, R
- Subjects
Luminescent solar concentrator, photovoltaics, performance reporting ,34 Chemical Sciences ,Settore ING-IND/22 - Scienza e Tecnologia dei Materiali ,photovoltaics ,General Energy ,Rare Diseases ,Clinical Research ,Taverne ,ddc:333.7 ,SDG 7 - Affordable and Clean Energy ,luminescent solar concentrator ,luminescent solar concentrators ,SDG 7 – Betaalbare en schone energie ,40 Engineering - Abstract
Fair and meaningful device per- formance comparison among luminescent solar concentrator- photovoltaic (LSC-PV) reports cannot be realized without a gen- eral consensus on reporting stan- dards in LSC-PV research. There- fore, it is imperative to adopt standardized characterization protocols for these emerging types of PV devices that are consistent with other PV devices. This commentary highlights several common limitations in LSC literature and summarizes the best practices moving for- ward to harmonize with standard PV reporting, considering the greater nuances present with LSC-PV. Based on these prac- tices, a checklist of actionable items is provided to help stan- dardize the characterization/re- porting protocols and offer a set of baseline expectations for au- thors, reviewers, and editors. The general consensus combined with the checklist will ultimately guide LSC-PV research towards reliable and meaningful ad- vances.
- Published
- 2022
26. Using Redox Titrations to Probe the Role of Trivalent Impurity Ions in the Ferromagnetism of Colloidal EuS Nanocrystals
- Author
-
Sidney E. Creutz, Sarah L. Stoll, Derak James, Daniel R. Gamelin, Rachel Fainblat, Alexander G Rachkov, and Michael C. De Siena
- Subjects
Materials science ,Nanostructure ,Spintronics ,Condensed Matter::Other ,General Chemical Engineering ,Doping ,General Chemistry ,Condensed Matter::Mesoscopic Systems and Quantum Hall Effect ,Condensed Matter::Materials Science ,Colloid ,Ferromagnetism ,Nanocrystal ,Impurity ,Chemical physics ,Redox titration ,Materials Chemistry ,Condensed Matter::Strongly Correlated Electrons - Abstract
EuS and related ferromagnetic semiconductors have long been model materials for spintronic device functionality because of their ability to generate highly spin-polarized electrical currents. Altho...
- Published
- 2020
27. Synthesis and Spectroscopy of Emissive, Surface-Modified, Copper-Doped Indium Phosphide Nanocrystals
- Author
-
Brandi M. Cossairt, Forrest W. Eagle, Daniel R. Gamelin, M. Elizabeth Mundy, and Kira E. Hughes
- Subjects
Materials science ,General Chemical Engineering ,Inorganic chemistry ,Doping ,Surface modified ,Biomedical Engineering ,chemistry.chemical_element ,Copper ,chemistry.chemical_compound ,chemistry ,Nanocrystal ,Indium phosphide ,General Materials Science ,Spectroscopy - Abstract
Aminophosphine precursors were used to synthesize copper-doped indium phosphide nanocrystals (InP NCs) via direct doping in a slow-injection bottom-up method and postsynthetic cation exchange. By b...
- Published
- 2020
28. Modeling Equilibrium Binding at Quantum Dot Surfaces Using Cyclic Voltammetry
- Author
-
Brandi M. Cossairt, Danielle A. Henckel, Daniel M. Kroupa, Michael J. Enright, Daniel R. Gamelin, and Noushyar Panahpour Eslami
- Subjects
Chemistry ,Mechanical Engineering ,Nanoparticle ,Bioengineering ,General Chemistry ,Condensed Matter Physics ,Small molecule ,chemistry.chemical_compound ,Ferrocene ,Quantum dot ,Oxidation state ,Physical chemistry ,Molecule ,General Materials Science ,Physics::Chemical Physics ,Cyclic voltammetry ,Equilibrium constant - Abstract
Cyclic voltammetry is demonstrated as a useful method to model equilibrium binding between quantum dots and redox active small molecules. Specifically, the interaction of a library of ferrocene derivatives with CdSe quantum dots is examined. For the strongly interacting systems, ferrocene carboxylic acid (FcCOOH) and ferrocene hexanethiol (Fc-hexSH), the binding equilibria can be quantitatively deduced by modeling the cyclic voltammetry data. This modeling allows extraction of the diffusion coefficients, equilibrium constants associated with both the reduced and oxidized species, and forward and reverse rates associated with binding for both the reduced and oxidized species. Taken together these data give direct insight into the binding of small molecules to quantum-dot surfaces as a function of oxidation state, critical information for the design of quantum dots as photoredox catalysts and charge transfer mediators.
- Published
- 2020
29. Two-Dimensional van der Waals Nanoplatelets with Robust Ferromagnetism
- Author
-
Daniel R. Gamelin, Annie Regan, Jiun-Haw Chu, Xiaodong Xu, Michael C. De Siena, Zhong Lin, Sidney E. Creutz, James J. De Yoreo, Qianni Jiang, Guomin Zhu, Kyle T. Kluherz, and Paul Malinowski
- Subjects
Nanostructure ,Materials science ,Condensed matter physics ,Magnetic circular dichroism ,Mechanical Engineering ,Bioengineering ,02 engineering and technology ,General Chemistry ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,Magnetization ,symbols.namesake ,Ferromagnetism ,Nanocrystal ,Monolayer ,symbols ,General Materials Science ,van der Waals force ,0210 nano-technology ,Spectroscopy - Abstract
We have synthesized unique colloidal nanoplatelets of the two-dimensional (2D) van der Waals ferromagnet CrI3 and have characterized these nanoplatelets structurally, magnetically, and by magnetic circular dichroism spectroscopy. The CrI3 nanoplatelets have lateral dimensions of ∼25 nm and thicknesses of only ∼4 nm, corresponding to just a few CrI3 monolayers. Magnetic and magneto-optical measurements demonstrate robust 2D ferromagnetic ordering with Curie temperatures similar to bulk CrI3, despite their small size. These data also show magnetization steps akin to those observed in micron-sized few-layer 2D sheets associated with concerted spin-reversal of individual CrI3 layers within few-layer van der Waals stacks. Similar data have also been obtained for CrBr3 and anion-alloyed Cr(I1–xBrx)3 nanoplatelets. These results represent the first example of lateral nanostructures of 2D van der Waals ferromagnets of any composition. The demonstration of robust ferromagnetism at nanometer lateral dimensions open...
- Published
- 2020
30. Spin-orbit–coupled exciton-polariton condensates in lead halide perovskites
- Author
-
Andrew P. Schlaus, Yanan Dai, Yongping Fu, Doyk Hwang, Michael S. Spencer, Daniel R. Gamelin, Xiaoyang Zhu, and Matthew D. Smith
- Subjects
Condensed Matter::Quantum Gases ,Physics ,Range (particle radiation) ,Multidisciplinary ,Condensed matter physics ,Spintronics ,Condensed Matter::Other ,business.industry ,Exciton ,Materials Science ,SciAdv r-articles ,Physics::Optics ,Condensed Matter::Mesoscopic Systems and Quantum Hall Effect ,Computer Science::Hardware Architecture ,Coupling (physics) ,Polariton ,Physical and Materials Sciences ,Photonics ,Orbit (control theory) ,business ,Spin (physics) ,Research Article ,Applied Physics - Abstract
Description, Spin orbital–coupled exciton-polaritons and spin-polarized condensates are found in lead halide perovskites., Spin-orbit coupling (SOC) is responsible for a range of spintronic and topological processes in condensed matter. Here, we show photonic analogs of SOCs in exciton-polaritons and their condensates in microcavities composed of birefringent lead halide perovskite single crystals. The presence of crystalline anisotropy coupled with splitting in the optical cavity of the transverse electric and transverse magnetic modes gives rise to a non-Abelian gauge field, which can be described by the Rashba-Dresselhaus Hamiltonian near the degenerate points of the two polarization modes. With increasing density, the exciton-polaritons with pseudospin textures undergo phase transitions to competing condensates with orthogonal polarizations. Unlike their pure photonic counterparts, these exciton-polaritons and condensates inherit nonlinearity from their excitonic components and may serve as quantum simulators of many-body SOC processes.
- Published
- 2021
31. Universal Machine Learning Framework for Defect Predictions in Zinc Blende Semiconductors
- Author
-
Daniel R. Gamelin, Laura M. Jacoby, Scott T. Dunham, Maria K. Y. Chan, Robert Biegaj, Xiaofeng Xiang, and Arun Mannodi-Kanakkithodi
- Subjects
Condensed Matter::Materials Science ,Materials science ,Semiconductor ,Condensed matter physics ,chemistry ,law ,business.industry ,General Decision Sciences ,chemistry.chemical_element ,Universal Turing machine ,Zinc ,business ,law.invention - Abstract
Point defects or impurities are either naturally present in semiconductors or may be intentionally introduced to tune their electronic and optical properties. The nature of impurity energy levels can strongly influence the performance of a semiconductor in applications ranging from solar cells to photodiodes to infrared sensors to qubits for quantum computing. In this work, we develop a framework powered by machine learning (ML) and high-throughput density functional theory (DFT) computations for the prediction and screening of functional impurities in group IV, III-V, and II-VI zinc blende semiconductors. Elements spanning the length and breadth of the periodic table are considered as impurity atoms at the cation, anion, or interstitial sites in supercells of 34 candidate semiconductors, leading to a chemical space of 12,000 points, 10% of which are used to generate a DFT dataset of charge dependent defect formation energies. Descriptors based on tabulated elemental properties, defect coordination environment, and relevant semiconductor properties are used to train ML regression models for the DFT computed properties, resulting in statistical predictions of the neutral state formation energies and charge transition levels of all possible impurities in the given set of compounds. Kernel ridge regression, Gaussian process regression, and neural networks, with appropriate feature selection and hyperparameter optimization, are seen to yield similar predictive performances and meaningful uncertainty estimates. We apply the ML framework to screen all impurities with lower formation energy than dominant native defects in all group IV, III-V, and II-VI zinc blende semiconductors. An online tool resulting from this work for predicting and visualizing defect properties in semiconductors is made available on github.
- Published
- 2021
32. Spinodal Decomposition During Anion Exchange in Colloidal Mn2+-Doped CsPbX3 (X = Cl, Br) Perovskite Nanocrystals
- Author
-
Daniel R. Gamelin, David E. Sommer, Michael C. De Siena, Sidney E. Creutz, and Scott T. Dunham
- Subjects
Materials science ,Ion exchange ,Spinodal decomposition ,General Chemical Engineering ,Doping ,chemistry.chemical_element ,02 engineering and technology ,General Chemistry ,Manganese ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,0104 chemical sciences ,chemistry ,Nanocrystal ,Materials Chemistry ,Physical chemistry ,0210 nano-technology ,Luminescence ,Perovskite (structure) - Abstract
Manganese(II)-doped cesium–lead–chloride (Mn2+:CsPbCl3) perovskite nanocrystals have recently been developed as promising luminescent materials and attractive candidates for white-light generation....
- Published
- 2019
33. Structural Diversity in Cesium Bismuth Halide Nanocrystals
- Author
-
Hongbin Liu, Daniel R. Gamelin, Xiaosong Li, Sidney E. Creutz, and Mitchell E. Kaiser
- Subjects
Materials science ,Ion exchange ,Trimethylsilyl ,General Chemical Engineering ,Inorganic chemistry ,Structural diversity ,chemistry.chemical_element ,Halide ,02 engineering and technology ,General Chemistry ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,0104 chemical sciences ,Bismuth ,chemistry.chemical_compound ,chemistry ,Nanocrystal ,Caesium ,Materials Chemistry ,0210 nano-technology ,Luminescence - Abstract
Cesium bismuth halides (Cs-Bi-X) have recently been the subject of considerable attention as possible less-toxic alternatives to lead halide perovskites for luminescence and photovoltaics applications, but the full range of synthetically accessible Cs-Bi-X compositions has not been thoroughly explored, and some inconsistent results have appeared in the literature. Here, we have used a combination of hot-injection synthesis and post-synthetic anion exchange to prepare Cs-Bi-X nanocrystals with many structures and compositions, including several that have not previously been characterized. The structural and optical properties of Cs3BiX6 (X = Cl, Br, I) nanocrystals and Cs3Bi2X9 (X = Cl, Br, I) nanoplatelets are reported, and interconversion of these structures between different halide compositions is demonstrated through anion exchange using trimethylsilyl halides. Notably, we find that anion exchange can be used to access structural polymorphs not readily prepared through direct synthesis. In particular, ...
- Published
- 2019
34. Single-Source Vapor Deposition of Quantum-Cutting Yb3+:CsPb(Cl1–xBrx)3 and Other Complex Metal-Halide Perovskites
- Author
-
Daniel M. Kroupa, Joo Yeon D. Roh, Daniel R. Gamelin, Matthew D. Smith, Rayne T. Anderson, and Matthew J. Crane
- Subjects
Materials science ,business.industry ,Quantum cutting ,Energy Engineering and Power Technology ,Photodetection ,Chemical vapor deposition ,Metal ,Semiconductor ,Photovoltaics ,Mechanochemistry ,visual_art ,Materials Chemistry ,Electrochemistry ,visual_art.visual_art_medium ,Chemical Engineering (miscellaneous) ,Optoelectronics ,Electrical and Electronic Engineering ,business ,Quantum - Abstract
Metal-halide semiconductors exhibit attractive properties for a host of applications including photovoltaics, solid-state lighting, and photodetection. Among the remarkable recent developments is t...
- Published
- 2019
35. Photoluminescence Saturation in Quantum-Cutting Yb3+-Doped CsPb(Cl1–xBrx)3 Perovskite Nanocrystals: Implications for Solar Downconversion
- Author
-
Tyler J. Milstein, Christian S. Erickson, Matthew J. Crane, and Daniel R. Gamelin
- Subjects
Materials science ,Photoluminescence ,Quantum cutting ,Physics::Optics ,Halide ,02 engineering and technology ,010402 general chemistry ,01 natural sciences ,Condensed Matter::Materials Science ,Condensed Matter::Superconductivity ,Physical and Theoretical Chemistry ,Quantum ,Perovskite (structure) ,business.industry ,Doping ,Quantum Physics ,021001 nanoscience & nanotechnology ,0104 chemical sciences ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,General Energy ,Nanocrystal ,Optoelectronics ,Condensed Matter::Strongly Correlated Electrons ,0210 nano-technology ,business ,Saturation (chemistry) - Abstract
Yb3+-doped halide perovskites have recently emerged as extraordinarily promising materials for solar spectral downconversion applications because of their extremely high photoluminescence quantum y...
- Published
- 2019
36. Anion Exchange and the Quantum-Cutting Energy Threshold in Ytterbium-Doped CsPb(Cl1–xBrx)3 Perovskite Nanocrystals
- Author
-
Christian S. Erickson, James J. De Yoreo, Tyler J. Milstein, Kyle T. Kluherz, Daniel R. Gamelin, and Daniel M. Kroupa
- Subjects
Ytterbium ,Photon ,Photoluminescence ,Materials science ,Dopant ,Mechanical Engineering ,Doping ,Halide ,chemistry.chemical_element ,Bioengineering ,02 engineering and technology ,General Chemistry ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,Molecular physics ,Nanocrystal ,chemistry ,Picosecond ,General Materials Science ,0210 nano-technology - Abstract
Colloidal halide perovskite nanocrystals of CsPbCl3 doped with Yb3+ have demonstrated remarkably high sensitized photoluminescence quantum yields (PLQYs), approaching 200%, attributed to a picosecond quantum-cutting process in which one photon absorbed by the nanocrystal generates two photons emitted by the Yb3+ dopants. This quantum-cutting process is thought to involve a charge-neutral defect cluster within the nanocrystal’s internal volume. We demonstrate that Yb3+-doped CsPbCl3 nanocrystals can be converted postsynthetically to Yb3+-doped CsPb(Cl1–xBrx)3 nanocrystals without compromising the desired high PLQYs. Nanocrystal energy gaps can be tuned continuously from Eg ≈ 3.06 eV (405 nm) in CsPbCl3 down to Eg ≈ 2.53 eV (∼490 nm) in CsPb(Cl0.25Br0.75)3 while retaining a constant PLQY above 100%. Reducing Eg further causes a rapid drop in PLQY, interpreted as reflecting an energy threshold for quantum cutting at approximately twice the energy of the Yb3+ 2F7/2 → 2F5/2 absorption threshold. These data dem...
- Published
- 2019
37. Detailed-balance analysis of Yb3+:CsPb(Cl1−xBrx)3 quantum-cutting layers for high-efficiency photovoltaics under real-world conditions
- Author
-
Daniel R. Gamelin, Matthew J. Crane, and Daniel M. Kroupa
- Subjects
Photoluminescence ,Photon ,Materials science ,Tandem ,Renewable Energy, Sustainability and the Environment ,business.industry ,Photovoltaic system ,Detailed balance ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,Pollution ,0104 chemical sciences ,Nuclear Energy and Engineering ,Photovoltaics ,Limit (music) ,Environmental Chemistry ,Optoelectronics ,0210 nano-technology ,business ,Quantum - Abstract
Yb3+-Doped lead-halide perovskites (Yb3+:CsPb(Cl1−xBrx)3) have emerged as unique materials combining strong, tunable broadband absorption with near-infrared photoluminescence quantum yields (PLQYs) approaching 200% at ambient temperature. These remarkable properties make Yb3+:CsPb(Cl1−xBrx)3 an extremely promising candidate for spectral shaping in high-efficiency photovoltaic devices. Previous theoretical assessments of such “downconversion” devices have predicted single-junction efficiencies up to 40%, but have been highly idealized. Real materials like Yb3+:CsPb(Cl1−xBrx)3 have practical limitations such as constrained band-gap and PL energies, non-directional emission, and an excitation-power-dependent PLQY. Hence, it is unclear whether Yb3+:CsPb(Cl1−xBrx)3, or any other non-ideal quantum-cutting material, can indeed boost the efficiencies of real high-performance PV. Here, we examine the thermodynamic, detailed-balance efficiency limit of Yb3+:CsPb(Cl1−xBrx)3 on different existing PV under real-world conditions. Among these, we identify silicon heterojunction technology as very promising for achieving significant performance gains when paired with Yb3+:CsPb(Cl1−xBrx)3, and we predict power-conversion efficiencies of up to 32% for this combination. Surprisingly, PL saturation does not negate the improved device performance. Calculations accounting for actual hourly incident solar photon fluxes show that Yb3+:CsPb(Cl1−xBrx)3 boosts power-conversion efficiencies at all times of day and year in two representative geographic locations. Predicted annual energy yields are comparable to those of tandem perovskite-on-silicon technologies, but without the need for current matching, tracking, or additional electrodes and inverters. In addition, we show that band-gap optimization in real quantum cutters is inherently a function of their PLQY and the ability to capture that PL. These results provide key design rules needed for development of high-efficiency quantum-cutting photovoltaic devices based on Yb3+:CsPb(Cl1−xBrx)3.
- Published
- 2019
38. Quantum-cutting Yb3+-doped perovskite nanocrystals for monolithic bilayer luminescent solar concentrators
- Author
-
Daniel R. Gamelin, Tyler J. Milstein, J. Devin MacKenzie, Christine K. Luscombe, Daniel M. Kroupa, and Theodore A. Cohen
- Subjects
Waveguide (electromagnetism) ,Photoluminescence ,Photon ,Materials science ,Renewable Energy, Sustainability and the Environment ,business.industry ,Bilayer ,Doping ,02 engineering and technology ,General Chemistry ,021001 nanoscience & nanotechnology ,Nanocrystal ,Optoelectronics ,General Materials Science ,0210 nano-technology ,Luminescence ,business ,Perovskite (structure) - Abstract
Luminescent solar concentrators (LSCs) can concentrate direct and diffuse solar radiation spatially and energetically to help reduce the overall area of solar cells needed to meet current energy demands. LSCs require luminophores that absorb large fractions of the solar spectrum, emit photons into a light-capture medium with high photoluminescence quantum yields (PLQYs), and do not absorb their own photoluminescence. Luminescent nanocrystals (NCs) with near or above unity PLQYs and Stokes shifts large enough to avoid self-absorption losses are well-suited to meet these needs. In this work, we describe LSCs based on quantum-cutting Yb3+:CsPb(Cl1−xBrx)3 NCs that have documented PLQYs as high as ∼200%. Through a combination of solution-phase 1D LSC measurements and modeling, we demonstrate that Yb3+:CsPbCl3 NC LSCs show negligible intrinsic reabsorption losses, and we use these data to model the performance of large-scale 2D LSCs based on these NCs. We further propose a new and unique monolithic bilayer LSC device architecture that contains a Yb3+:CsPb(Cl1−xBrx)3 NC top layer above a second narrower-gap LSC bottom layer (e.g., based on CuInS2 NCs), both within the same waveguide and interfaced with the same Si PV for conversion. We extend the modeling to predict the flux gains of such bilayer devices. Because of the exceptionally high PLQYs of Yb3+:CsPb(Cl1−xBrx)3 NCs, the optimized bilayer device has a projected flux gain of 63 for dimensions of 70 × 70 × 0.1 cm3, representing performance enhancement of at least 19% over the optimized CuInS2 LSC alone.
- Published
- 2019
39. Copper’s Role in the Photoluminescence of Ag1–xCuxInS2 Nanocrystals, from Copper-Doped AgInS2 (x ∼ 0) to CuInS2 (x = 1)
- Author
-
Daniel R. Gamelin, Sarah R. Ostheller, Kira E. Hughes, and Heidi D. Nelson
- Subjects
Photoluminescence ,Materials science ,Mechanical Engineering ,Doping ,chemistry.chemical_element ,Bioengineering ,02 engineering and technology ,General Chemistry ,Electronic structure ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,Copper ,Crystallography ,Nanocrystal ,chemistry ,General Materials Science ,0210 nano-technology - Abstract
A series of Ag1–xCuxInS2 nanocrystals (NCs) spanning from 0 ≤ x ≤ ∼1 was synthesized by partial cation exchange to identify copper’s contributions to the electronic structure and spectroscopic prop...
- Published
- 2018
40. Modular Zwitterion-Functionalized Poly(Isopropyl Methacrylate) Polymers for Hosting Luminescent Lead-Halide Perovskite Nanocrystals
- Author
-
Nico A. Bricker, Daniel R. Gamelin, Yunping Huang, Tyler J. Milstein, J. Devin MacKenzie, Theodore A. Cohen, Christine K. Luscombe, and Connor S. Juhl
- Subjects
chemistry.chemical_classification ,chemistry.chemical_compound ,Photoluminescence ,Materials science ,Nanocrystal ,chemistry ,Chemical engineering ,Zwitterion ,Polymer ,Thin film ,Luminescence ,Isopropyl ,Perovskite (structure) - Abstract
Inorganic lead-halide perovskite nanocrystals (NCs) are an exciting class of luminescent materials with high defect tolerance and broad spectral tunability, but such NCs are vulnerable to degradation under ambient conditions. Here, we report a class of modular zwitterion-functionalized isopropyl methacrylate polymers designed to stabilize a wide variety of perovskite NCs of different compositions, while also enabling processing in green solvents. Specifically, we report polymers in which the zwitterion spacing is tuned to accommodate the different lattice parameters of CsPb(Cl1-xBrx)3 and CsPbI3 NCs, and we report partially fluorinated polymers prepared to accommodate the needs of infrared-emitting NCs. We show that as-synthesized CsPbBr3, CsPbI3, and Yb3+:CsPbCl3 NCs are easily transferred into these zwitterionic polymers via a simple ligand-exchange procedure. These NC/polymer composites were then cast into thin films that showed substantially improved photoluminescence (PL) and stability compared with more conventional NC/polymer films. Specifically, CsPbBr3 and CsPbI3 NCs in films of their appropriately designed polymers had PL quantum yields of ~90% and ~80%, respectively. PL quantum yields decreased under continuous illumination, but self-healed completely after dark storage. We also found that all the NC compositions studied here maintain their PL quantum yields in NC/polymer composite films even after 1 year of ambient storage. These encouraging results demonstrate the utility of such modular zwitterion-functionalized polymers for hosting specific perovskite NCs, potentially opening avenues for robust new photonic applications of this important class of NCs.
- Published
- 2021
41. Moiré trions in MoSe
- Author
-
Xi, Wang, Jiayi, Zhu, Kyle L, Seyler, Pasqual, Rivera, Huiyuan, Zheng, Yingqi, Wang, Minhao, He, Takashi, Taniguchi, Kenji, Watanabe, Jiaqiang, Yan, David G, Mandrus, Daniel R, Gamelin, Wang, Yao, and Xiaodong, Xu
- Abstract
Transition metal dichalcogenide moiré bilayers with spatially periodic potentials have emerged as a highly tunable platform for studying both electronic
- Published
- 2021
42. Highly Anisotropic Excitons and Multiple Phonon Bound States in a Van der Waals Antiferromagnetic Insulator
- Author
-
Jordan Fonseca, Di Xiao, Daniel R. Gamelin, Qianni Jiang, Chong Wang, Yong Wang, Jiun-Haw Chu, Wang Yao, Kyle Hwangbo, Geoffrey Diederich, Xiaodong Xu, and Qi Zhang
- Subjects
Photoluminescence ,Band gap ,Exciton ,Biomedical Engineering ,FOS: Physical sciences ,Bioengineering ,02 engineering and technology ,010402 general chemistry ,Linear dichroism ,01 natural sciences ,Condensed Matter::Materials Science ,Mesoscale and Nanoscale Physics (cond-mat.mes-hall) ,Antiferromagnetism ,General Materials Science ,Electrical and Electronic Engineering ,Anisotropy ,Physics ,Condensed matter physics ,Condensed Matter - Mesoscale and Nanoscale Physics ,Condensed Matter::Other ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,Condensed Matter::Mesoscopic Systems and Quantum Hall Effect ,Magnetic susceptibility ,Atomic and Molecular Physics, and Optics ,0104 chemical sciences ,Zigzag ,0210 nano-technology - Abstract
Two-dimensional semiconducting systems, such as quantum wells and transition metal dichalcogenides, are the foundations to investigate low dimensional light-matter interactions. To date, the study of elementary photoexcitation, namely the exciton, in 2D semiconductors with intrinsic magnetic order remains a challenge due to the lack of suitable material platforms. Here, we report an observation of excitons coupled to zigzag antiferromagnetic order in the layered antiferromagnetic insulator NiPS3 using both photoluminescence (PL) and optical reflection spectroscopy. The exciton exhibits a linewidth as narrow as ~350 ueV with near unity linear polarization in the PL spectrum. As the thicknesses of samples is reduced from five layers to bilayers, the PL intensity is drastically suppressed and eventually vanishes in monolayers, consistent with the calculated bandgap being highly indirect for both bilayer and monolayer. We observed strong linear dichroism (LD) over a broad spectra range, which shares the same optical anisotropy axis, being locked to the zigzag direction, as the exciton PL. Both LD and the degree of linear polarization in the exciton PL decrease as the temperature increases and become negligible above the Neel temperature. These observations suggest both optical quantities are probes of the symmetry breaking magnetic order parameter. In addition, a sharp resonance in the LD spectrum is observed with an energy near the exciton PL. There exist over ten exciton-A1g phonon bound states on its high energy side, which likely result from the strong modulation of the ligand-to-metal charge transfer energy by strong electron-lattice interactions. Our work establishes NiPS3 as a new 2D platform for exploring magneto-exciton physics with strong correlations, as well as a building block for 2D heterostructures for engineering physical phenomena with time reversal symmetry breaking., Comment: to be appear in Nature Nanotechnology
- Published
- 2021
- Full Text
- View/download PDF
43. State of the art and prospects for halide perovskite nanocrystals
- Author
-
Maryna I. Bodnarchuk, Mengyu Gao, Junzhi Ye, Anunay Samanta, Liang Li, Yangning Zhang, Joseph M. Luther, Maksym V. Kovalenko, Sudhir Kumar, Angshuman Nag, Javad Shamsi, Xian-Gang Wu, Iván Mora-Seró, Li Na Quan, Brian A. Korgel, Ivan G. Scheblykin, Hilmi Volkan Demir, Prashant V. Kamat, Peidong Yang, Julian A. Steele, Anirban Dutta, Maarten B. J. Roeffaers, Omar F. Mohammed, Lakshminarayana Polavarapu, Chih-Jen Shih, Ke Xu, Muhan Cao, Samuel D. Stranks, Haibo Zeng, Qiao Zhang, Fei Yan, Amrita Dey, Robert L. Z. Hoye, Apurba De, Chuang Han, Lata Chouhan, Ilka Vincon, Jin Z. Zhang, Narayan Pradhan, Johan Hofkens, Osman M. Bakr, Andrey L. Rogach, Eva Bladt, Jacek K. Stolarczyk, Xiaoming Li, Peter Müller-Buschbaum, Sara Bals, Julia Pérez-Prieto, Anuraj S. Kshirsagar, Haizheng Zhong, Liberato Manna, Yanxiu Li, Marina Gerhard, Jun Yin, Ziyu Wang, Manuel A. Scheel, Yue Wang, Seung Kyun Ha, Dong Hee Son, Jochen Feldmann, Raquel E. Galian, Handong Sun, Vasudevanpillai Biju, Yong Yan, Daniel R. Gamelin, William A. Tisdale, Roman Krahne, Qiaoliang Bao, Elke Debroye, Tushar Debnath, Demir, Hilmi Volkan, Dey, Amrita [0000-0003-2372-2172], De, Apurba [0000-0002-3042-0642], Debroye, Elke [0000-0003-1087-4759], Ha, Seung Kyun [0000-0003-2967-1097], Yin, Jun [0000-0002-1749-1120], Gao, Mengyu [0000-0003-1385-7364], Shamsi, Javad [0000-0003-4684-5407], Debnath, Tushar [0000-0002-8108-4482], Cao, Muhan [0000-0002-7988-7219], Scheel, Manuel A [0000-0003-0508-6694], Kumar, Sudhir [0000-0002-2994-7084], Steele, Julian A [0000-0001-7982-4413], Zhang, Yangning [0000-0001-5511-955X], Dutta, Anirban [0000-0001-9915-6985], Rogach, Andrey L [0000-0002-8263-8141], Nag, Angshuman [0000-0003-2308-334X], Samanta, Anunay [0000-0003-1551-0209], Korgel, Brian A [0000-0001-6242-7526], Shih, Chih-Jen [0000-0002-5258-3485], Gamelin, Daniel R [0000-0003-2888-9916], Zeng, Haibo [0000-0002-0281-3617], Zhong, Haizheng [0000-0002-2662-7472], Sun, Handong [0000-0002-2261-7103], Demir, Hilmi Volkan [0000-0003-1793-112X], Scheblykin, Ivan G [0000-0001-6059-4777], Mora-Seró, Iván [0000-0003-2508-0994], Stolarczyk, Jacek K [0000-0001-7935-4204], Zhang, Jin Z [0000-0003-3437-912X], Hofkens, Johan [0000-0002-9101-0567], Luther, Joseph M [0000-0002-4054-8244], Pérez-Prieto, Julia [0000-0002-5833-341X], Li, Liang [0000-0003-3898-0641], Manna, Liberato [0000-0003-4386-7985], Bodnarchuk, Maryna I [0000-0001-6597-3266], Kovalenko, Maksym V [0000-0002-6396-8938], Roeffaers, Maarten BJ [0000-0001-6582-6514], Pradhan, Narayan [0000-0003-4646-8488], Mohammed, Omar F [0000-0001-8500-1130], Bakr, Osman M [0000-0002-3428-1002], Yang, Peidong [0000-0003-4799-1684], Müller-Buschbaum, Peter [0000-0002-9566-6088], Kamat, Prashant V [0000-0002-2465-6819], Bao, Qiaoliang [0000-0002-6971-789X], Zhang, Qiao [0000-0001-9682-3295], Krahne, Roman [0000-0003-0066-7019], Galian, Raquel E [0000-0001-8703-4403], Stranks, Samuel D [0000-0002-8303-7292], Bals, Sara [0000-0002-4249-8017], Biju, Vasudevanpillai [0000-0003-3650-9637], Tisdale, William A [0000-0002-6615-5342], Hoye, Robert LZ [0000-0002-7675-0065], Polavarapu, Lakshminarayana [0000-0002-9040-5719], and Apollo - University of Cambridge Repository
- Subjects
light-emitting devices ,General Physics and Astronomy ,Nanotechnology ,02 engineering and technology ,010402 general chemistry ,01 natural sciences ,7. Clean energy ,photocatalysts ,metal-halide perovskite nanocrystals ,lead-free perovskite nanocrystals ,Photovoltaics ,General Materials Science ,Nanoscience & Nanotechnology ,Perovskite (structure) ,Electronic properties ,Physics ,business.industry ,perovskite nanoplatelets ,General Engineering ,021001 nanoscience & nanotechnology ,0104 chemical sciences ,ddc ,Chemistry ,photovoltaics ,perovskite nanocubes ,perovskite nanowires ,lasers ,photodetectors ,Nanocrystal ,2307 Química Física ,0210 nano-technology ,business ,Engineering sciences. Technology - Abstract
Financiado para publicación en acceso aberto: Universidade de Vigo/CISUG Metal-halide perovskites have rapidly emerged as one of the most promising materials of the 21st century, with many exciting properties and great potential for a broad range of applications, from photovoltaics to optoelectronics and photocatalysis. The ease with which metal-halide perovskites can be synthesized in the form of brightly luminescent colloidal nanocrystals, as well as their tunable and intriguing optical and electronic properties, has attracted researchers from different disciplines of science and technology. In the last few years, there has been a significant progress in the shape-controlled synthesis of perovskite nanocrystals and understanding of their properties and applications. In this comprehensive review, researchers having expertise in different fields (chemistry, physics, and device engineering) of metal-halide perovskite nanocrystals have joined together to provide a state of the art overview and future prospects of metal-halide perovskite nanocrystal research. Ministerio de Ciencia e Innovación | Ref. RYC2018-026103-I Agencia Estatal de Investigación | Ref. CTQ2017-82711-P Ministerio de Economía y Competitividad | Ref. MDM-2015-0538 Agencia Estatal de Investigación | Ref. PID2019-107314RB-I00
- Published
- 2021
44. Coherent Spin Precession and Lifetime-Limited Spin Dephasing in CsPbBr
- Author
-
Matthew J, Crane, Laura M, Jacoby, Theodore A, Cohen, Yunping, Huang, Christine K, Luscombe, and Daniel R, Gamelin
- Abstract
Carrier spins in semiconductor nanocrystals are promising candidates for quantum information processing. Using a combination of time-resolved Faraday rotation and photoluminescence spectroscopies, we demonstrate optical spin polarization and coherent spin precession in colloidal CsPbBr
- Published
- 2020
45. Coherent Spin Precession and Lifetime-Limited Spin Dephasing in CsPbBr3 Perovskite Nanocrystals
- Author
-
Matthew J. Crane, Yunping Huang, Laura M. Jacoby, Christine K. Luscombe, Theodore A. Cohen, and Daniel R. Gamelin
- Subjects
Photoluminescence ,Materials science ,FOS: Physical sciences ,Physics::Optics ,Bioengineering ,02 engineering and technology ,7. Clean energy ,symbols.namesake ,Condensed Matter::Materials Science ,Faraday effect ,Mesoscale and Nanoscale Physics (cond-mat.mes-hall) ,General Materials Science ,Quantum information ,Spin (physics) ,Perovskite (structure) ,Condensed Matter - Materials Science ,Condensed matter physics ,Spins ,Spintronics ,Condensed Matter - Mesoscale and Nanoscale Physics ,Condensed Matter::Other ,Mechanical Engineering ,Materials Science (cond-mat.mtrl-sci) ,General Chemistry ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,Condensed Matter::Mesoscopic Systems and Quantum Hall Effect ,3. Good health ,symbols ,Precession ,Condensed Matter::Strongly Correlated Electrons ,0210 nano-technology - Abstract
Carrier spins in semiconductor nanocrystals are promising candidates for quantum information processing. Using a combination of time-resolved Faraday rotation and photoluminescence spectroscopies, we demonstrate optical spin polarization and coherent spin precession in colloidal CsPbBr3 nanocrystals that persists up to room temperature. By suppressing the influence of inhomogeneous hyperfine fields with a small applied magnetic field, we demonstrate inhomogeneous hole transverse spin-dephasing times (T2*) that approach the nanocrystal photoluminescence lifetime, such that nearly all emitted photons derive from coherent hole spins. Thermally activated LO phonons drive additional spin dephasing at elevated temperatures, but coherent spin precession is still observed at room temperature. These data reveal several major distinctions between spins in nanocrystalline and bulk CsPbBr3 and open the door for using metal-halide perovskite nanocrystals in spin-based quantum technologies., Accepted for publication at Nano Letters, 11/19/20
- Published
- 2020
46. Yb3+ speciation and energy-transfer dynamics in quantum-cutting Yb3+ -doped CsPbCl3 perovskite nanocrystals and single crystals
- Author
-
Joo Yeon D. Roh, Daniel Biner, Daniel R. Gamelin, Matthew J. Crane, Karl Krämer, Tyler J. Milstein, and Matthew D. Smith
- Subjects
Photoluminescence ,Materials science ,Physics and Astronomy (miscellaneous) ,Doping ,Relaxation (NMR) ,02 engineering and technology ,021001 nanoscience & nanotechnology ,01 natural sciences ,Excited state ,0103 physical sciences ,Intermediate state ,General Materials Science ,Atomic physics ,010306 general physics ,0210 nano-technology ,Spectroscopy ,Energy (signal processing) ,Perovskite (structure) - Abstract
${\mathrm{Yb}}^{3+}$-doped inorganic metal-halide perovskites $(\mathrm{Y}{\mathrm{b}}^{3+}:\mathrm{CsPb}{X}_{3}$, $X=\mathrm{Cl},\mathrm{Br})$ have recently been discovered to display highly efficient quantum cutting, in which the energy from individual blue or UV photons absorbed by the material is reemitted in the form of pairs of near-infrared photons by ${\mathrm{Yb}}^{3+}$ dopants. Experimental photoluminescence quantum yields approaching 200% have been reported. As the first quantum-cutting materials that combine such high-photoluminescence quantum yields with strong, broadband absorption in the visible, these materials offer unique opportunities for enhancing the efficiencies of solar technologies. Little is known about the fundamental origins of this quantum cutting, however. Here, we describe variable-temperature and time-resolved photoluminescence studies of ${\mathrm{Yb}}^{3+}:\mathrm{CsPb}{\mathrm{Cl}}_{3}$ in two disparate forms--colloidal nanocrystals and macroscopic single crystals. Both forms show very similar spectroscopic properties, demonstrating that quantum cutting is an intrinsic property of the ${\mathrm{Yb}}^{3+}:\mathrm{CsPb}{X}_{3}$ composition itself. Diverse ${\mathrm{Yb}}^{3+}$ speciation is observed in both forms by low-temperature photoluminescence spectroscopy, but remarkably, quantum cutting is dominated by the same specific ${\mathrm{Yb}}^{3+}$ species in both cases. Time-resolved photoluminescence measurements provide direct evidence of the previously hypothesized intermediate state in the quantum-cutting mechanism. This intermediate state mediates relaxation from the photogenerated excited state of the perovskite to the emissive excited state of ${\mathrm{Yb}}^{3+}$, and hence is of critical mechanistic importance. At room temperature, this intermediate state is populated within a few picoseconds and has a decay time of only \ensuremath{\sim}7 ns in both nanocrystalline and single-crystal ${\mathrm{Yb}}^{3+}:\mathrm{CsPb}{\mathrm{Cl}}_{3}$. The mechanistic implications of these observations are discussed. These results provide valuable information about characteristics of this unique quantum cutter that will aid its optimization and application in solar technologies.
- Published
- 2020
47. Insight into the Spin Properties in Undoped and Mn-Doped CdSe/CdS-Seeded Nanorods by Optically Detected Magnetic Resonance
- Author
-
Efrat Lifshitz, Adam K. Budniak, Yahel Barak, Joanna Dehnel, Anjani P. Nagvenkar, Daniel R. Gamelin, and Itay Meir
- Subjects
Materials science ,Condensed matter physics ,Doping ,Degrees of freedom ,General Engineering ,General Physics and Astronomy ,Semiconductor nanostructures ,02 engineering and technology ,Scientific field ,Condensed Matter::Mesoscopic Systems and Quantum Hall Effect ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,0104 chemical sciences ,Condensed Matter::Materials Science ,Condensed Matter::Strongly Correlated Electrons ,General Materials Science ,Nanorod ,Mn doped ,0210 nano-technology ,Spin (physics) - Abstract
Controlling the spin degrees of freedom of photogenerated species in semiconductor nanostructures via magnetic doping is an emerging scientific field that may play an important role in the developm...
- Published
- 2020
48. Electron Beam Infrared Nano-Ellipsometry of Individual Indium Tin Oxide Nanocrystals
- Author
-
David J. Masiello, Jose J. Araujo, Daniel R. Gamelin, Jacob A. Busche, Arpan Maiti, Juan Carlos Idrobo, Jon P. Camden, and Agust Olafsson
- Subjects
Materials science ,business.industry ,Mechanical Engineering ,Electron energy loss spectroscopy ,Physics::Optics ,chemistry.chemical_element ,Bioengineering ,General Chemistry ,Condensed Matter Physics ,Indium tin oxide ,Condensed Matter::Materials Science ,chemistry ,Ellipsometry ,Physics::Atomic and Molecular Clusters ,Optoelectronics ,General Materials Science ,Thin film ,Surface plasmon resonance ,Spectroscopy ,business ,Indium ,Plasmon - Abstract
Leveraging recent advances in electron energy monochromation and aberration correction, we record the spatially resolved infrared plasmon spectrum of individual tin-doped indium oxide nanocrystals using electron energy-loss spectroscopy (EELS). Both surface and bulk plasmon responses are measured as a function of tin doping concentration from 1-10 atomic percent. These results are compared to theoretical models, which elucidate the spectral detuning of the same surface plasmon resonance feature when measured from aloof and penetrating probe geometries. We additionally demonstrate a unique approach to retrieving the fundamental dielectric parameters of individual semiconductor nanocrystals via EELS. This method, devoid from ensemble averaging, illustrates the potential for electron-beam ellipsometry measurements on materials that cannot be prepared in bulk form or as thin films.
- Published
- 2020
49. A control and characterization of spin degrees of freedom of photo-generated carriers in colloidal seeded nanorods - via magnetic doping
- Author
-
Yahel Barak, Adam K. Budniak, Anjani Nagnvenkar, Efrat Lifshitz, Joanna Dehnel, Itay Meir, and Daniel R. Gamelin
- Subjects
Colloid ,Materials science ,Condensed matter physics ,Doping ,Degrees of freedom ,Nanorod ,Spin-½ ,Characterization (materials science) - Published
- 2020
50. Hydrothermal Synthesis and Solid-State Laser Refrigeration of Ytterbium-Doped Potassium Lutetium Fluoride (KLF) Microcrystals
- Author
-
Xiaojing Xia, Anupum Pant, Xuezhe Zhou, Elena Dobretsova, Alex Bard, Matthew Lim, Joo Yeon Roh, Daniel R. Gamelin, and Peter Pauzauskie
- Abstract
Fluoride crystals, due to their low phonon energies, are attractive hosts of trivalent lanthanide ions for applications in upconverting phosphors, quantum information science, and solid-state laser refrigeration. In this article, we report the rapid, low-cost hydrothermal synthesis of potassium lutetium fluoride (KLF) microcrystals for applications in solid-state laser refrigeration. Four crystalline phases were synthesized, namely orthorhombic K2LuF5 (Pnma), trigonal KLuF4 (P3121), orthorhombic KLu2F7 (Pna21), and cubic KLu3F10 (Fm3m), with each phase exhibiting unique microcrystalline morphologies. Luminescence spectra and emission lifetimes of the four crystalline phases were characterized based on the point-group symmetry of trivalent cations. Laser refrigeration was measured by observing both the optomechanical eigenfrequencies of microcrystals on cantilevers in vacuum, and also the Brownian dynamics of optically trapped microcrystals in water. Among all four crystalline phases, the most significant cooling was observed for 10%Yb:KLuF4 with cooling of 8.6 $\pm$ 2.1 K below room temperature. Reduced heating was observed with 10%Yb:K2LuF5
- Published
- 2020
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.