Paper
27 March 2022 Improvement of blue green absorption of reflection mode GaAlAs photocathode with different nanostructures
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Proceedings Volume 12169, Eighth Symposium on Novel Photoelectronic Detection Technology and Applications; 121696L (2022) https://doi.org/10.1117/12.2624811
Event: Eighth Symposium on Novel Photoelectronic Detection Technology and Applications, 2021, Kunming, China
Abstract
Underwater photoelectric detection equipment with 532 nm laser as light source needs to match specific photocathodes to achieve the purpose of high quantum efficiency and narrow-band response. NEA GaAlAs photocathodes have a series of advantages, such as high quantum efficiency, adjustable spectral response cutoff threshold and long lifetime to serve as the devices for underwater detection. However, the quantum efficiency of GaAlAs photocathodes is not high enough to meet the actual detection requirements. In addition, micro-nano structures on the surface of materials have been proved to be an effective method to improve optical absorption. In this paper, four kinds of nanostructures including square column, cylinder, square cone and cone are designed. By the finite difference time domain method, results show that the optical absorptivity of reflection-mode GaAlAs photocathodes can be effectively improved. The optical absorptivity of square cone nanostructures increases and tends to be stable with the increase of filling factor. The optical absorptivity is approximately 100% at blue-green light region including 532 nm, and has an abrupt cutoff feature. Otherwise, when the absorptivity of square cone nanostructures is high and stable, the most intense light absorption part will move to the top of nanostructures with the increase of filling factor, thus effectively shortening the electron transport distance and improving the photoemission capability.
© (2022) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Shiman Li, Yijun Zhang, Feng Shi, Gangcheng Jiao, Ziheng Wang, and Kaimin Zhang "Improvement of blue green absorption of reflection mode GaAlAs photocathode with different nanostructures", Proc. SPIE 12169, Eighth Symposium on Novel Photoelectronic Detection Technology and Applications, 121696L (27 March 2022); https://doi.org/10.1117/12.2624811
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KEYWORDS
Nanostructures

Absorption

Light sources

Quantum efficiency

Electron transport

Finite-difference time-domain method

Gallium arsenide

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