Near-band-gap photoemission spectroscopy experiments were performed on p-GaN and p-InGaN/GaN photocathodes activated to negative electron affinity. The photoemission quantum yield of the InGaN samples with more than 5% of indium drops by more than 1 order of magnitude when the temperature is decreased while it remains constant for lower indium content. This drop is attributed to a freezing of photoelectron transport in p-InGaN due to electron localization in the fluctuating potential induced by the alloy disorder. This interpretation is supported by the disappearance at low temperature of the peak in the photoemission spectrum that corresponds to the contribution of the photoelectrons relaxed at the bottom of the InGaN conduction band.
|Original language||English (US)|
|Journal||Physical Review Letters|
|State||Published - Nov 18 2022|
Bibliographical noteKAUST Repository Item: Exported on 2022-12-09
Acknowledgements: We thank Aurélien David for fruitful discussions and Yuh-Renn Wu for fruitful discussions and access to the drift-diffusion charge control (DDCC) solver. This work was supported by the French National Research Agency (ANR, grants ELENID No. ANR-17-CE24-0040-01 and TECCLON No. ANR-20-CE05-0037-01), by the Simons Foundation (Grants No. 601952 J. S. S., No. 601954 C. W., and No. 601944 J.-P. B.), the National Science Foundation (NSF) RAISE program (Grant No. DMS-1839077), ARPA-E, U.S. Department of Energy (program DE-EE0007096), the UCSB Solid State Lighting and Energy Electronics Center, and KACST-KAUST-UCSB Solid State Lighting Program (SSLP).
This publication acknowledges KAUST support, but has no KAUST affiliated authors.
ASJC Scopus subject areas
- Physics and Astronomy(all)