Search

Your search keyword '"Oliver, Robert D. J."' showing total 34 results
Start Over Author "Oliver, Robert D. J."
34 results on '"Oliver, Robert D. J."'

1. Strong coupling in molecular systems: a simple predictor employing routine optical measurements

Author

Rider, Marie S., Johnson, Edwin C., Bates, Demetris, Wardley, William P., Gordon, Robert H., Oliver, Robert D. J., Armes, Steven P., Leggett, Graham J., and Barnes, William L.

Subjects
Physics - Optics, Condensed Matter - Mesoscale and Nanoscale Physics, Physics - Chemical Physics
Abstract

We provide a simple method that enables readily acquired experimental data to be used to predict whether or not a candidate molecular material may exhibit strong coupling. Specifically, we explore the relationship between the hybrid molecular/photonic (polaritonic) states and the bulk optical response of the molecular material. For a given material this approach enables a prediction of the maximum extent of strong coupling (vacuum Rabi splitting), irrespective of the nature of the confined light field. We provide formulae for the upper limit of the splitting in terms of the molar absorption coefficient, the attenuation coefficient, the extinction coefficient (imaginary part of the refractive index) and the absorbance. To illustrate this approach we provide a number of examples, we also discuss some of the limitations of our approach.

Published
2024

3. Strong coupling in molecular systems: a simple predictor employing routine optical measurements

Author

Rider Marie S., Johnson Edwin C., Bates Demetris, Wardley William P., Gordon Robert H., Oliver Robert D. J., Armes Steven P., Leggett Graham J., and Barnes William L.

Subjects
strong coupling, polariton, molecular states, lorentz oscillator, Physics, QC1-999
Abstract

We provide a simple method that enables readily acquired experimental data to be used to predict whether or not a candidate molecular material may exhibit strong coupling. Specifically, we explore the relationship between the hybrid molecular/photonic (polaritonic) states and the bulk optical response of the molecular material. For a given material, this approach enables a prediction of the maximum extent of strong coupling (vacuum Rabi splitting), irrespective of the nature of the confined light field. We provide formulae for the upper limit of the splitting in terms of the molar absorption coefficient, the attenuation coefficient, the extinction coefficient (imaginary part of the refractive index) and the absorbance. To illustrate this approach, we provide a number of examples, and we also discuss some of the limitations of our approach.

Published
2024
Full Text
View/download PDF

7. The Role of the Organic Cation in Developing Efficient Green Perovskite LEDs Based on Quasi‐2D Perovskite Heterostructures

Author

Ramadan, Alexandra J., primary, Jeong, Woo Hyeon, additional, Oliver, Robert D. J., additional, Jiang, Junke, additional, Dasgupta, Akash, additional, Yuan, Zhongcheng, additional, Smith, Joel, additional, Lee, Jae Eun, additional, Motti, Silvia G., additional, Gough, Olivia, additional, Li, Zhenlong, additional, Herz, Laura M., additional, Johnston, Michael B., additional, Choi, Hyosung, additional, Even, Jacky, additional, Katan, Claudine, additional, Lee, Bo Ram, additional, and Snaith, Henry J., additional

Published
2023
Full Text
View/download PDF

8. The Role of the Organic Cation in Developing Efficient Green Perovskite LEDs Based on Quasi‐2D Perovskite Heterostructures.

Author

Ramadan, Alexandra J., Jeong, Woo Hyeon, Oliver, Robert D. J., Jiang, Junke, Dasgupta, Akash, Yuan, Zhongcheng, Smith, Joel, Lee, Jae Eun, Motti, Silvia G., Gough, Olivia, Li, Zhenlong, Herz, Laura M., Johnston, Michael B., Choi, Hyosung, Even, Jacky, Katan, Claudine, Lee, Bo Ram, and Snaith, Henry J.

Subjects
PEROVSKITE, HETEROSTRUCTURES, LIGHT emitting diodes, METAL halides, CRYSTAL structure, ELECTRONIC structure
Abstract

Two dimensional/three‐dimensional (2D/3D) metal halide perovskite heterostructures have attracted great interest in photovoltaic and light‐emitting diode (LEDs) applications. In both, their implementation results in an improvement in device efficiency yet the understanding of these heterostructures remains incomplete. In this work the role of organic cations, essential for the formation of 2D perovskite structures is unraveled, in a range of metal halide perovskite heterostructures. These heterostructures are used to fabricate efficient green perovskite LEDs and a strong dependence between cation content and device performance is shown. The crystal structure, charge‐carrier transport and dynamics, and the electronic structure of these heterostructures are studied and it is shown that the presence of crystalline 2D perovskite inhibits electron injection and ultimately lowers device performance. This work highlights the importance of optimizing the composition of these heterostructures in ensuring optimal device performance across all parameters and suggests that developing routes to inject charge‐carriers directly into 2D perovskite structures will be important in ensuring the continued development of perovskite LEDs based on these heterostructures. [ABSTRACT FROM AUTHOR]

Published
2024
Full Text
View/download PDF

10. Ultrasonic Spray Deposition of a Passivating Agent for Spray-Coated, Methylammonium-Free Perovskite Solar Cells.

Author

Cassella, Elena J., Thornber, Timothy, Oliver, Robert D. J., O'Kane, Mary E., Spooner, Emma L. K., Kilbride, Rachel C., Catley, Thomas E., Game, Onkar S., Ramadan, Alexandra J., and Lidzey, David G.

Subjects
SOLAR cells, PEROVSKITE, PASSIVATION, SURFACE passivation, SURFACE preparation, OPEN-circuit voltage
Abstract

Defect management in perovskite solar cells (PSCs) via surface passivation has become a cornerstone in maximizing both stability and solar-to-electrical power conversion efficiency (PCE) of devices by reducing defect densities and/or improving energetic alignment between the perovskite and charge-transporting layers. Despite this, few reports explore the use of roll-to-roll compatible technologies to deposit such interfacial treatments, limiting the applicability of passivation in real-world contexts. In this work, iso-butylammonium bromide (i-BABr) is spray-coated onto a Cs0.15FA0.85PbI2.85Cl0.15 perovskite surface which is deposited using gas-assisted ultrasonic spray coating. It is found that i-BABr treatments result in the formation of a quasi-2D perovskite layer. The spray-coated surface treatment results in an impressive 80 mV improvement in the median open-circuit voltage with respect to untreated devices. Importantly, the spray-coated passivation results in very similar positive benefits to the application of spin-coated treatments demonstrating the promise of the spray-passivation methodology. It is shown that devices created in this manner demonstrate PCEs of up to 21.0% (19.4% stabilized), representing the highest reported efficiency for one-step, spray-coated methylammonium-free PSCs. This work represents the first demonstration of a spray-coated surface passivation treatment that is compatible with high-throughput, roll-to-roll processing. [ABSTRACT FROM AUTHOR]

Published
2024
Full Text
View/download PDF

11. Impact of Interface Energetic Alignment and Mobile Ions on Charge Carrier Accumulation and Extraction in p‐i‐n Perovskite Solar Cells

Author

Xu, Weidong, primary, Hart, Lucy J. F., additional, Moss, Benjamin, additional, Caprioglio, Pietro, additional, Macdonald, Thomas J., additional, Furlan, Francesco, additional, Panidi, Julianna, additional, Oliver, Robert D. J., additional, Pacalaj, Richard A., additional, Heeney, Martin, additional, Gasparini, Nicola, additional, Snaith, Henry J., additional, Barnes, Piers R. F., additional, and Durrant, James R., additional

Published
2023
Full Text
View/download PDF

13. Alumina Nanoparticle Interfacial Buffer Layer for Low‐Bandgap Lead‐Tin Perovskite Solar Cells.

Author

Jin, Heon, Farrar, Michael D., Ball, James M., Dasgupta, Akash, Caprioglio, Pietro, Narayanan, Sudarshan, Oliver, Robert D. J., Rombach, Florine M., Putland, Benjamin W. J., Johnston, Michael B., and Snaith, Henry J.

Subjects
SOLAR cells, PHOTOVOLTAIC power systems, BUFFER layers, NANOPARTICLES, ALUMINUM oxide, SOLAR spectra, PEROVSKITE
Abstract

Mixed lead‐tin (Pb:Sn) halide perovskites are promising absorbers with narrow‐bandgaps (1.25–1.4 eV) suitable for high‐efficiency all‐perovskite tandem solar cells. However, solution processing of optimally thick Pb:Sn perovskite films is notoriously difficult in comparison with their neat‐Pb counterparts. This is partly due to the rapid crystallization of Sn‐based perovskites, resulting in films that have a high degree of roughness. Rougher films are harder to coat conformally with subsequent layers using solution‐based processing techniques leading to contact between the absorber and the top metal electrode in completed devices, resulting in a loss of VOC, fill factor, efficiency, and stability. Herein, this study employs a non‐continuous layer of alumina nanoparticles distributed on the surface of rough Pb:Sn perovskite films. Using this approach, the conformality of the subsequent electron‐transport layer, which is only tens of nanometres in thickness is improved. The overall maximum‐power‐point‐tracked efficiency improves by 65% and the steady‐state VOC improves by 28%. Application of the alumina nanoparticles as an interfacial buffer layer also results in highly reproducible Pb:Sn solar cell devices while simultaneously improving device stability at 65 °C under full spectrum simulated solar irradiance. Aged devices show a six‐fold improvement in stability over pristine Pb:Sn devices, increasing their lifetime to 120 h. [ABSTRACT FROM AUTHOR]

Published
2023
Full Text
View/download PDF

14. Synergistic Surface Modification of Tin–Lead Perovskite Solar Cells

Author

Hu, Shuaifeng, primary, Zhao, Pei, additional, Nakano, Kyohei, additional, Oliver, Robert D. J., additional, Pascual, Jorge, additional, Smith, Joel A., additional, Yamada, Takumi, additional, Truong, Minh Anh, additional, Murdey, Richard, additional, Shioya, Nobutaka, additional, Hasegawa, Takeshi, additional, Ehara, Masahiro, additional, Johnston, Michael B., additional, Tajima, Keisuke, additional, Kanemitsu, Yoshihiko, additional, Snaith, Henry J., additional, and Wakamiya, Atsushi, additional

Published
2023
Full Text
View/download PDF

16. A Universal Perovskite Nanocrystal Ink for High‐Performance Optoelectronic Devices

Author

Song, Hochan, primary, Yang, Jonghee, additional, Jeong, Woo Hyeon, additional, Lee, Jeongjae, additional, Lee, Tack Ho, additional, Yoon, Jung Won, additional, Lee, Hajin, additional, Ramadan, Alexandra J., additional, Oliver, Robert D. J., additional, Cho, Seong Chan, additional, Lim, Seul Gi, additional, Jang, Ji Won, additional, Yu, Zhongkai, additional, Oh, Jae Taek, additional, Jung, Eui Dae, additional, Song, Myoung Hoon, additional, Park, Sung Heum, additional, Durrant, James R., additional, Snaith, Henry J., additional, Lee, Sang Uck, additional, Lee, Bo Ram, additional, and Choi, Hyosung, additional

Published
2022
Full Text
View/download PDF

17. Thermally Stable Perovskite Solar Cells by All-Vacuum Deposition

Author

Yuan, Qimu, primary, Lohmann, Kilian B., additional, Oliver, Robert D. J., additional, Ramadan, Alexandra J., additional, Yan, Siyu, additional, Ball, James M., additional, Christoforo, M. Greyson, additional, Noel, Nakita K., additional, Snaith, Henry J., additional, Herz, Laura M., additional, and Johnston, Michael B., additional

Published
2022
Full Text
View/download PDF

20. Scalable processing for realizing 21.7%-efficient all-perovskite tandem solar modules

Author

Xiao, Ke, primary, Lin, Yen-Hung, additional, Zhang, Mei, additional, Oliver, Robert D. J., additional, Wang, Xi, additional, Liu, Zhou, additional, Luo, Xin, additional, Li, Jia, additional, Lai, Donny, additional, Luo, Haowen, additional, Lin, Renxing, additional, Xu, Jun, additional, Hou, Yi, additional, Snaith, Henry J., additional, and Tan, Hairen, additional

Published
2022
Full Text
View/download PDF

21. Solvent-Free Method for Defect Reduction and Improved Performance of p-i-n Vapor-Deposited Perovskite Solar Cells

Author

Lohmann, Kilian B., primary, Motti, Silvia G., additional, Oliver, Robert D. J., additional, Ramadan, Alexandra J., additional, Sansom, Harry C., additional, Yuan, Qimu, additional, Elmestekawy, Karim A., additional, Patel, Jay B., additional, Ball, James M., additional, Herz, Laura M., additional, Snaith, Henry J., additional, and Johnston, Michael B., additional

Published
2022
Full Text
View/download PDF

25. Understanding and suppressing non-radiative losses in methylammonium-free wide-bandgap perovskite solar cells

Author

Oliver, Robert D. J., primary, Caprioglio, Pietro, additional, Peña-Camargo, Francisco, additional, Buizza, Leonardo R. V., additional, Zu, Fengshuo, additional, Ramadan, Alexandra J., additional, Motti, Silvia G., additional, Mahesh, Suhas, additional, McCarthy, Melissa M., additional, Warby, Jonathan H., additional, Lin, Yen-Hung, additional, Koch, Norbert, additional, Albrecht, Steve, additional, Herz, Laura M., additional, Johnston, Michael B., additional, Neher, Dieter, additional, Stolterfoht, Martin, additional, and Snaith, Henry J., additional

Published
2022
Full Text
View/download PDF

30. A piperidinium salt stabilizes efficient metal-halide perovskite solar cells

Author

Lin, Yen-Hung, primary, Sakai, Nobuya, additional, Da, Peimei, additional, Wu, Jiaying, additional, Sansom, Harry C., additional, Ramadan, Alexandra J., additional, Mahesh, Suhas, additional, Liu, Junliang, additional, Oliver, Robert D. J., additional, Lim, Jongchul, additional, Aspitarte, Lee, additional, Sharma, Kshama, additional, Madhu, P. K., additional, Morales‐Vilches, Anna B., additional, Nayak, Pabitra K., additional, Bai, Sai, additional, Gao, Feng, additional, Grovenor, Chris R. M., additional, Johnston, Michael B., additional, Labram, John G., additional, Durrant, James R., additional, Ball, James M., additional, Wenger, Bernard, additional, Stannowski, Bernd, additional, and Snaith, Henry J., additional

Published
2020
Full Text
View/download PDF

34. Bandgap-universal passivation enables stable perovskite solar cells with low photovoltage loss.

Author

Lin YH, Vikram, Yang F, Cao XL, Dasgupta A, Oliver RDJ, Ulatowski AM, McCarthy MM, Shen X, Yuan Q, Christoforo MG, Yeung FSY, Johnston MB, Noel NK, Herz LM, Islam MS, and Snaith HJ

Abstract

The efficiency and longevity of metal-halide perovskite solar cells are typically dictated by nonradiative defect-mediated charge recombination. In this work, we demonstrate a vapor-based amino-silane passivation that reduces photovoltage deficits to around 100 millivolts (>90% of the thermodynamic limit) in perovskite solar cells of bandgaps between 1.6 and 1.8 electron volts, which is crucial for tandem applications. A primary-, secondary-, or tertiary-amino-silane alone negatively or barely affected perovskite crystallinity and charge transport, but amino-silanes that incorporate primary and secondary amines yield up to a 60-fold increase in photoluminescence quantum yield and preserve long-range conduction. Amino-silane-treated devices retained 95% power conversion efficiency for more than 1500 hours under full-spectrum sunlight at 85°C and open-circuit conditions in ambient air with a relative humidity of 50 to 60%.

Published
2024
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results