Open AccessA study of spectral response for reflection-mode GaN photocathodes in UVA band
Author(s) -
Gazi Hao,
Benkang Chang,
Xinlong Chen,
Xiaohui Wang,
Jianhua Zhao,
Youlong Xu,
Muchun Jin
Publication year - 2013
Publication title -
wuli xuebao
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.199
H-Index - 47
ISSN - 1000-3290
DOI - 10.7498/aps.62.097901
Subject(s) - photocathode , quantum efficiency , materials science , optoelectronics , optics , wavelength , reflection (computer programming) , doping , metalorganic vapour phase epitaxy , layer (electronics) , physics , electron , nanotechnology , epitaxy , quantum mechanics , computer science , programming language
In order to understand the spectral response characteristic of the NEA GaN photocathodes at UVA band, three samples grown by MOCVD with different emission layer thickness and doping concentration were activated in the ultra-high vacuum system, and their spectral response were tested online. We fit the experimental quantum efficiency with illumination wavelength between 0.25—0.35 μ by the use of reflection-mode GaN photocathode quantum efficiency formula and the least square approximation method. The back-interface compound rate and the slope of fitting line L are gained and the reflection-mode GaN photocathodes quantum efficiency is simulated with incident light wavelength at 0.35 μ. The results show that the back-interface compound rate and the slope of the fitting line L can reflect GaN photocathode response performance. When the back-interface compound rate of GaN photocathode is less than 105 cm/s and the thickness of the emission layer is set between 0.174—0.212 μ, the photocathode has optimal spectral response performance.