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Optically rough and physically flat transparent conductive (OR-PF) substrates facilitate the performance improvement of optoelectronic devices and functional glasses via simultaneously enabling high-quality growth of functional layers and effective light management. This paper studies the effect of the interface morphology of the hole array pattern (HAP) and the pillar array pattern (PAP) on the far-field scattering properties of OR-PF substrates fabricated by spin-coating Al-doped ZnO (AZO) on nanoimprint-patterned glasses for improving the performance of superstrate-type thin-film solar cells. Theoretical calculation based on bidirectional scattering distribution function predicts that HAP with a period of 1.5 μm and a diameter of 1.3 μm [HAP(P1.5D1.3)] and the PAP(P1.0D0.5) interface morphology have a haze ratio in transmission (H

Novel CaGd2(WO4)4(1−x)(MoO4)4x:Eu3+ red phosphors were successfully prepared through a solid state method. The influence of molybdenum ions doping on the crystal structure and luminescence properties of CaGd2(WO4)4:Eu3+ were characterized in detail. Mo6+ ions are introduced into CaGd2(WO4)4 to induce the structure transformation from monoclinic scheelite with superspace group I2/b to tetragonal scheelite with superspace group I41/a. Under UV light excitation, CaGd2(WO4)4(1−x)(MoO4)4x:Eu3+ phosphors exhibit the strongest red emission dominated by the 5D0 → 7F2 transition of Eu3+ at 617 nm. The luminescent properties of Eu3+ are improved significantly when Mo6+ ions are introduced into the host. In the case of x = 0.1, the emission intensity of CaGd2(WO4)3.6(MoO4)0.4:Eu3+ phosphor is enhanced by 50% compared to undoped one, and the colour purity and quantum yield are calculated to be 95.3% and 53.5%, respectively. Meanwhile, the as-prepared phosphor exhibited unusual temperature sensitive emission, and the thermal quenching process was explained resultantly through the configurational coordinate diagram. Furthermore, to better understand the red emission behavior, the Judd–Oflet theory was employed to analyze the radiative transition intensity parameters of CaGd2(WO4)4 phosphors.

An optically rough and physically flat (OR-PF) TCO substrate was developed by spin-coating Al-doped ZnO thin film on glass substrate patterned with random pyramidal morphology to enhance the light absorption in superstrate-type thin-film silicon solar cells without deteriorating the growth of photoactive layers. This substrate possesses flat surface with a root mean square roughness of 10.9 nm, high visible light transmittance of over 86%, a sheet resistance of 29.5 Ω/sq, and moderate light-scattering ability. A surface morphology of random pyramidal morphology was formed on the glass substrate by replicating the pyramidal surface texture of a ZnO thin film with the room-temperature nanoimprint technique. Employed as the front electrode of hydrogenated amorphous Si single-junction solar cells, this OR-PF substrate enabled a Voc of 0.91 eV, an FF of 0.71, a Jsc gain of approximately 8%, and an efficiency gain of approximately 20% with respect to the AZO-coated flat glass substrate. The Jsc gain is attributed to the enhancement in the light absorption of a-Si:H solar cells triggered by the diffraction behaviour of the interfacial pyramidal morphology, while the achievement of large Voc and FF is ascribed to the improvement in the growth quality of the photoactive layers. Based on the calculation results of the bidirectional scattering distribution function, this substrate empowers comparable intensity of the diffraction peaks for 600–700 nm wavelength light but scatters less light away from the specular direction with respect to the conventional pyramid-textured ZnO substrate. This OR-PF substrate would enable efficient photon management and the growth of high-quality photoactive materials simultaneously for thin-film silicon solar cells.

Al doped zinc magnesium oxide (Zn1-xMgxO:Al) thin films with tunable optical bandgap (3.48 eV–3.66 eV) and resistivity level of 10−3 Ω·cm were prepared by sol-gel process. The effect of the Mg incorporation on the structural, electrical and optical properties was studied by analyzing the results of X-ray diffraction diffractograms, transmittance spectra, Hall measurement and X-ray photoelectron spectroscopy. Mg incorporation influences the crystal structure through reducing the c-axis lattice constant. Blueshift of absorption edge with Mg incorporation manifests the bandgap widening effect. Mg incorporation also increases the film resistivity through decreasing Hall mobility and carrier concentration. Employed as the front electrode, these Zn1-xMgxO:Al thin films improved the blue response of hydrogenated amorphous silicon solar cells through reducing the optical loss in ZnO:Al. Zn1-xMgxO:Al with x ≤ 0.13 enables an open-circuit voltage (Voc) of about 0.9 V and a fill factor (FF) of about 0.7. The Zn0.87Mg0.13O:Al empowers a gain of about 9% in short-circuit current density relative to ZnO:Al via the bandgap widening and the improved refractive-index-matching, while the Zn0.80Mg0.20O:Al deteriorates Voc and FF through increasing the downward band bending at the Zn1-xMgxO:Al/p-a-SiC:H interface. This work paves the way for applying the sol-gel derived Zn1-xMgxO:Al thin films to optoelectronic devices such as ultraviolet light detector, ultraviolet light emitting diodes and solar cells.

We report on the fabrication and characterization of InAs/GaAs chirped multilayer quantum-dot superluminescent diodes (CMQD-SLDs) with and without direct Si doping in QDs. It was found that both the output power and the spectral width of the CMQD-SLDs were significantly enhanced by direct Si doping in the QDs. The output power and spectral width have been increased by approximately 18.3% and 40%, respectively. Moreover, we shortened the cavity length of the doped CMQD-SLD and obtained a spectral width of 106 nm. In addition, the maximum output power and spectral width of the CMQD-SLD doped directly with Si can be further increased to 16.6 mW and 114 nm, respectively, through anti-reflection coating and device packaging. The device exhibited the smallest spectral dip of 0.2 dB when the spectrum was widest. The improved performances of the doped CMQD-SLD can be attributed to the direct doping of Si in the QDs, optimization of device structure and device packaging.

A material platform of highly c-axis oriented Zn

We report compounds 5 (CG416) and 6 (CG428) as two first-in-class tropomyosin receptor kinase (TRK) degraders that target the intracellular kinase domain of TRK. Degraders 5 and 6 reduced levels of the tropomyosin 3 (TPM3)-TRKA fusion protein in KM12 colorectal carcinoma cells and inhibited downstream PLCγ1 signaling at sub-nanomolar concentrations. Both degraders also degraded human wild-type TRKA with similar potency. Interestingly, both degraders, especially 6, showed selectivity for the degradation of endogenous TPM3-TRKA over ectopically expressed ATP/GTP binding protein-like 4 (AGBL4)-TRKB or ETS variant transcription factor 6 (ETV6)-TRKC fusion proteins in KM12 cells. Global proteomic profiling assays demonstrated that 5 is highly selective for the intended target. TPM3-TRKA protein degradation induced by 5 and 6 was further confirmed to be mediated through cereblon and the ubiquitin-proteasome system. Compared with the parental TRK kinase inhibitor, both degraders exhibited higher potency for inhibiting growth of KM12 cells. Moreover, both 5 and 6 showed good plasma exposure levels in mice. Therefore, 5 and 6 are valuable chemical tool compounds for investigating the in vivo function of TRK fusion during tumorigenesis. Our study also paves the way for pharmacological degradation of TRK.

Aiming to realize high-speed optical transmitters for isolator-free telecommunication systems, 1.3 &mu, m p-modulation doped InGaAs/GaAs quantum dot (QD) lasers with a 400 &mu, m long cavity have been reported. Compared with the un-doped QD laser as a reference, the p-doped QD laser emits at ground state, with an ultra-low threshold current and a high maximum output power. The p-doped QD laser also shows enhanced dynamic characteristics, with a 10 Gb/s large-signal direct modulation rate and a 7.8 GHz 3dB-bandwidth. In addition, the p-doped QD laser exhibits a strong coherent optical feedback resistance, which might be beyond &minus, 9 dB.

Large nonlinear susceptibility that originates from strong electronic polarization enables ultrafast nonlinear optical devices. This work discovers that Mg incorporation has important contribution for enhancing second-order nonlinear susceptibility (χ (2)) and laser-induced surface-damage threshold of wurtzite ZnO epitaxial thin films deposited by radio-frequency magnetron sputtering method. Second-harmonic generation measurements derive that as-deposited Zn0.72Mg0.28O shows a gain of 48%, 77% and 33% in χ 33, χ 31 and χ 15 with respect to as-deposited ZnO. Specially, the annealed Zn0.72Mg0.28O has a χ 33 value of −57.0 ± 1.8 pm V−1, which gets comparable to that of LiNbO3 crystals. Triple-axis x-ray diffraction measurements conclude that the Mg incorporation should increase the χ (2) under optical frequency electric field by strengthening electronic polarization rather than increasing the residual strain in the film. Furthermore, the annealed Zn0.72Mg0.28O exhibits an increase of 48% in laser-induced surface-damage threshold relative to [11–20] ZnO crystals. These findings open the way of the Zn0.72Mg0.28O thin films to ultrafast nonlinear optical devices.

We report the effect of As flux rate (FR) during growth interruption (GI) after quantum dot (QD) deposition on the performances of InAs/InGaAsP/InP QDs and their lasers, grown by metal–organic chemical vapor deposition. The active region consists of seven layers of self-assembled InAs QDs separated by InGaAsP lattice-matched to InP. Room-temperature photoluminescence (PL) measurements show that both the PL peak intensity and emission wavelength of the active region increase with As FR. Temperature-dependent PLs reveal that the activation energies of the QDs from the ground state to higher energy level or barrier become greater with the increase of As FR, indicating less carrier thermal escape from the QDs to their barriers. These above observations can be attributed to the promoted migration and suppressed desorption of surface In atoms, leading to enlarged QDs with deepened energy levels and thus enhanced carrier quantum confinement effect. Moreover, a 6-μm-wide and 3-mm-long ridge-waveguide QD laser with the greatest As FR shows a lowest threshold current of 477 mA under pulse mode at room temperature, corresponding to a threshold current density of 379 A/cm2 per QD layer. Meanwhile, the laser exhibits the highest characteristic temperatures T0 and T1 of 331 K and 775 K, respectively, in the temperature range between 20 °C and 60 °C.

A series of red-emitting NaLaMgWO6:Sm3+,Eu3+ phosphors were successfully synthesized by the solid-state reaction method. The crystal structure, morphology and photoluminescence properties were investigated in detail. The NaLaMgWO6 compound has monoclinic structure with the space group C2/m. Upon excitation of the near-ultraviolet light, the Sm3+ singly doped and Eu3+singly doped phosphors exhibit red emission at 600 nm (4G5/2→6H7/2 transition of Sm3+) and 617 nm (5D0→7F2 transition of Eu3+), respectively, while the Sm3+, Eu3+ co-doped phosphors show the characteristic transition of Eu3+ whether excited by 397 or 406 nm. This indicates the existence of the energy transfer from Sm3+ to Eu3+ ions. Furthermore, the mechanism of energy transfer and energy transfer efficiency were confirmed by the decay time of Sm3+ ion in NaLaMgWO6:Sm3+,Eu3+ phosphors. The mechanism of energy transfer between Sm3+ and Eu3+ is proved to be dipole-dipole interaction, and the energy transfer efficiency of NaLa0.65MgWO6:0.05Sm3+,0.3Eu3+ phosphor is calculated to be 38.89%. The temperature dependent emission spectra demonstrate that the NaLaMgWO6:Sm3+,Eu3+ phosphor has a good thermal stability with an thermal activation energy ΔE of 0.241 eV. The CIE chromaticity coordinate is calculated to be (x = 0.661, y = 0.339).

In this paper, we systematically investigate the electronic structures of uncapped In(Ga)As nanoislands grown on pit-patterned GaAs(001) substrate by solving the Schrodinger equations with effective mass approximation, including composition profile (CP), band offset, strain induced deformation potentials, spin-orbit coupling and piezoelectric effect. For pure InAs epilayer, the shallow pit introduces red-shift to interband transition for all aspect ratios and the heavy-hole is localized by the confinement near the inclined hetero-interfaces in circular pit. For InGaAs alloy epilayer, the uniform CP and equilibrium CPs are considered. Due to the Indium segregation, the reduction of interband transition energy can be observed and the localized profile of heavy-hole moves upward visibly. Moreover, the strain relaxation analysis confirms better strain relaxation for nanoisland grown in shallow pit (tan β = 0.1) compared with same nanoisland grown on flat substrate. The results pave a guideline for designing site-controlled In(Ga)As nanoislands grown in pit for desired applications.

We numerically study and analyze the light absorption enhancement in thin crystalline silicon solar cell with dual interface gratings. The structure combines the front dielectric nanowalls and the sinusoidal plasmonic grating at back reflector. We show that having specific interfaces with well-chosen period, fill factor and height can allow more efficient dielectric and plasmonic modes coupling into active layer and can improve the solar cell performance. For 1 µm active layer case, the optimal result for the proposed structure achieves short-circuit current of ~23.6 mA/cm 2 , which performs over 50% better than flat solar cell structure, the short-circuit current of which is ~15.5 mA/cm 2 . In addition, the active layer thickness and angular analysis show that the proposed structure maintains its advantage over flat structure.

A compact design of all-optical diode with mode conversion function based on a two-dimensional photonic crystal waveguide and an L1 or L3 cavity is theoretically investigated. The proposed photonic crystal structures comprise a triangular arrangement of air holes embedded in a silicon substrate. Asymmetric light propagation is achieved via the spatial mode match/mismatch in the coupling region. The simulations show that at each cavity’s resonance frequency, the transmission efficiency of the structure with the L1 and L3 cavities reach 79% and 73%, while the corresponding unidirectionalities are 46 and 37 dB, respectively. The functional frequency can be controlled by simply adjusting the radii of specific air holes in the L1 and L3 cavities. The proposed structure can be used as a frequency filter, a beam splitter and has potential applications in all-optical integrated circuits.

High-work function (WF) transparent conductive thin films improve the performance of solar cells and organic light-emitting diodes by facilitating interfacial charge carrier transport. Al-doped ZnO (AZO) becomes a very promising transparent conductive material because of nontoxicity, abundant material resources, and low cost. To increase the WF of AZO without enhancing the series resistance of the device, a high-WF and low-resistance surface modifier of polycrystalline zinc molybdenum oxide (ZMO) was developed by utilizing thermal evaporation of MoO3 on the surface of AZO and a subsequent two-step annealing treatment. The first step of air annealing causes the formation of monoclinic ZnMoO4 nanocrystals in the ZMO modifier. This improves the WF of AZO from 3.83 to 4.86 eV by increasing the group electronegativity and cation oxidation state. Furthermore, the second step of N2 annealing decreases the resistivity of the polycrystalline ZMO by increasing the donor states of oxygen vacancies. The surface modification effect is verified by applying the ZMO-modified AZO to the front electrode of hydrogenated amorphous silicon thin-film solar cells. The low-resistance polycrystalline ZMO modifier not only increases light harvesting in the solar cells by improving interfacial refractive index matching but also improves the open-circuit voltage by modifying the interfacial band alignment. In particular, the modifier increases the fill factor by ca. 13% by reducing the series resistance of the device. These enable a gain of ca. 23% in photoelectric conversion efficiency compared to the unmodified AZO. The results suggest the feasibility to tune the WF and conductivity of a material independently.

A material platform of highly c-axis oriented Zn1-xMgxO thin films is developed for nonlinear planar waveguides and electro-optic modulators on Si. Mg content in the film greatly influences the quality of film growth. The second harmonic generation measurement and Maker-fringe analysis reveal that the second-order nonlinear susceptibility tensor element χ33 of the annealed Zn0.72Mg0.28O is approximately 4.2 times larger than that of ZnO. The propagation loss of 633 nm wavelength light in the annealed air/Zn0.72Mg0.28O/SiO2 slab waveguide is 0.68 ± 0.09 dB/cm and 0.48 ± 0.03 dB/cm for the TE0 and TM0 modes, respectively. These results suggest the great potential of the c-axis oriented Zn0.72Mg0.28O nonlinear planar waveguides for applications in on-chip optical interconnects.

In this paper, we systematically investigate the elastic strain relaxation of GeSi nanoislands grown on pit-patterned Si(001) substrate using finite element method. The multi-faceted GeSi nanoislands, including domes, barns and cupolas, inside square pit are modeled based on experimental observations. The impacts of aspect ratio, pit angle and pit filling level are analyzed, based on which a fitting expression is obtained to give a complete description of the strain relaxation. The pit angles corresponding to the best strain relaxation and to the critical point for better relaxation in pit are determined at filling levels (range from 0 to 1) and aspect ratios (range from 0.2 to 0.4). It can be seen that beyond a specific aspect ratio, the relaxation keeps worse than the case of same nanoisland grown on flat substrate, regardless of the pit angle and pit filling level. Moreover, based on the strain energy balance criterion, the conditions to ensure that nanoislands grown inside pit are demonstrated as well.

The packing densification of binary cylindrical particle mixtures under 3D mechanical vibrations was systematically studied in physical experiments. The influences of vibration time, frequency, amplitude, vibration acceleration (vibration intensity), particle size ratio of large versus small particles, composition of the binary mixtures (volume fraction of large particles), and container size (wall effects) on the packing density of the binary cylindrical particles were discussed and analyzed. The results indicate that for each fixed composition and size ratio, high packing density can be obtained by properly controlling the vibration conditions. Appropriate composition (e.g. 72 vol.%, volume fraction of large cylinders in current work) with large size ratio can contribute to the high packing density. Increasing the container size can reduce the container wall effects and obtain dense packing. Through extrapolation, the maximum packing density of binary cylindrical particles without container wall effects can reach about 0.8822, which agrees well with the proposed analytical model in literature.

Global data traffic is growing rapidly, and the demand for optoelectronic transceivers applied in data centers (DCs) is also increasing correspondingly. In this review, we first briefly introduce the development of optoelectronics transceivers in DCs, as well as the advantages of silicon photonic chips fabricated by complementary metal oxide semiconductor process. We also summarize the research on the main components in silicon photonic transceivers. In particular, quantum dot lasers have shown great potential as light sources for silicon photonic integration—whether to adopt bonding method or monolithic integration—thanks to their unique advantages over the conventional quantum-well counterparts. Some of the solutions for high-speed optical interconnection in DCs are then discussed. Among them, wavelength division multiplexing and four-level pulse-amplitude modulation have been widely studied and applied. At present, the application of coherent optical communication technology has moved from the backbone network, to the metro network, and then to DCs.

We report 25 Gb/s high-speed directly modulated ground-state operation of 1.3 μm InAs/GaAs quantum dot (QD) lasers grown by molecular beam epitaxy. The active region of the lasers consists of eight layers of p-doped InAs QDs with high uniformity and density. Ridge-waveguide lasers with a 3-μm-wide and 300-μm-long cavity show a low threshold current of 14.4 mA at 20°C and high temperature stability with a high characteristic temperature of 1208 K between 20°C and 70°C. Dynamic response measurements demonstrate that the laser has a 3 dB bandwidth of 7.7 GHz at 20°C and clearly opened eye diagrams even at high temperatures up to 75°C under a 25 Gb/s direct modulation rate.

We have screened 11 isoquinoline derivatives and α-methylene-γ-butyrolactones using the 3-(4,5-dimethylthi-azol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) cytotoxicity assay in HeLa and HEK-293T cells. Compound 2 was identified as potential anticancer agent. To further improve its therapeutic potential, this agent was incorporated into transferrin (Tf)-conjugated liposomes (LPs) for targeted delivery to tumor cells. We have demonstrated Tf-LP-Compound 2 have superior antitumor activity compared to non-targeted controls and the free drug. These data show Tf-LP-Compound 2 to be a promising agent that warrants further evaluation.