The temperature-dependent external quantum efficiency (EQE) droops of 265 nm, 275 nm, 280 nm, and 285 nm AlGaN-based ultraviolet-c light-emitting diodes (UVC-LEDs) differed in Al contents have been comprehensively investigated. The modifiedmodel (++) with the current-leakage related term,(), has been employed to analyze the recombination mechanisms in these UVC-LED samples. Experimental results reveal that, at relatively low electrical-current levels, the contribution of Shockley-Read-Hall (SRH) recombination exceeds those of the Auger recombination and carrier leakage. At relatively high electrical-current levels, the Auger recombination and carrier leakage jointly dominate the EQE droop phenomenon. Moreover, the inactivation efficiencies of 222 nm excimer lamp, 254 nm portable Mercury lamp, 265 nm, 280 nm, and 285 nm UVC-LED arrays in the inactivation ofhave been experimentally investigated, which could provide a technical reference for fighting against the new COVID-19.
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http://dx.doi.org/10.1088/1361-6528/acd5d7 | DOI Listing |
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January 2025
Department of Materials Science and Engineering, and Center for Functional Photonics (CFP), City University of Hong Kong, Hong Kong SAR, 999077, P. R. China.
Metal halide perovskite nanoplatelets (NPls) possess ultra-narrow photoluminescence (PL) bands tunable over the entire visible spectral range, which makes them promising for utilization in light-emitting diodes (LEDs) with spectrally pure emission colors. This calls for development of synthetic methods toward perovskite NPls with a high degree of control over both their thickness and lateral dimensions. A general strategy is developed to obtain such monodisperse CsPbI NPls through the control over the halide-to-lead ratio during heating-up reaction.
View Article and Find Full Text PDFNanomaterials (Basel)
January 2025
Key Laboratory of Optoelectronic Materials and Devices, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083, China.
Antimonide laser diodes, with their high performance above room temperature, exhibit significant potential for widespread applications in the mid-infrared spectral region. However, the laser's performance significantly degrades as the emission wavelength increases, primarily due to severe quantum-well hole leakage and significant non-radiative recombination. In this paper, we put up an active region with a high valence band offset and excellent crystalline quality with high luminescence to improve the laser's performance.
View Article and Find Full Text PDFEntropy (Basel)
December 2024
Departamento de Física, Universidad Técnica Federico Santa María, Av. España 1680, Valparaíso 2390123, Chile.
In this work, we study the magnetocaloric effect (MCE) in a working substance corresponding to a square lattice of spins with possible orientations, known as the "-state clock model". When the -state clock model has Q≥5 possible configurations, it presents the famous Berezinskii-Kosterlitz-Thouless (BKT) phase associated with vortex states. We calculate the thermodynamic quantities using Monte Carlo simulations for even numbers, ranging from Q=2 to Q=8 spin orientations per site in a lattice.
View Article and Find Full Text PDFACS Appl Mater Interfaces
January 2025
Anhui Huasun Energy Company, Limited, Xuancheng 242000, China.
A rear emitter with a p-type boron-doped hydrogenated amorphous silicon/nanocrystalline silicon [a-Si:H(p)/nc-Si:H(p)] stack was prepared for the silicon heterojunction (SHJ) solar cell to improve its short-circuit current density (). CO plasma treatment (CO PT) was applied to a-Si:H(p) to facilitate the crystallization of the subsequently deposited nc-Si:H(p). To evaluate the effect of the CO PT, two different nc-Si:H(p) layers with low and high crystallinity (χ) were investigated.
View Article and Find Full Text PDFACS Appl Mater Interfaces
January 2025
Key Laboratory of Luminescence and Optical Information, Beijing Jiaotong University, Ministry of Education, Beijing 100044, China.
Quasi-two-dimensional (quasi-2D) mixed-halide perovskites are a requisite for their applications in highly efficient blue perovskite light-emitting diodes (PeLEDs) owing to their strong quantum confinement effect and high exciton binding energy. The pace of quasi-2D blue PeLEDs is hindered primarily by two factors: challenges in precisely managing the phase distribution and defect-mediated nonradiative recombination losses. Herein, we utilize 2,2-diphenylethylamine (DPEA) with bulky steric hindrance to disturb the assembly process of a slender spacer host cation, 4-fluorophenylethylammonium (-F-PEA), enhancing phase distribution management in quasi-2D PeLEDs.
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