Theoretical exploration of quantum efficiency of AlxGa1 − xN monolayer photocathode with varying Al contents and ultra‐thin emission layer. (1st August 2020)

• Record Type: Journal Article
• Authors: Liu, Lei; Tian, Jian; Lu, Feifei
• Is Part Of: International journal of energy research. Volume 44:Number 13(2020)
• Page Start: 10962
• Page End: 10969
• Publication Date: 2020-08-01
• Subjects: AlGaN monolayer -- quantum efficiency -- ultra‐thin emission layer -- varying Al contents; Power resources -- Periodicals; Power (Mechanics) -- Periodicals; Power resources -- Research -- Periodicals; 621.042
• DOI: 10.1002/er.5733
• Languages: English
• ISSNs: 0363-907X

Abstract

Summary: To obtain high‐efficiency AlGaN monolayer photocathode, the quantum efficiency formulas of reflection‐mode and transmission‐mode Al x Ga1 − x N monolayer photocathode with varying Al contents and ultra‐thin emission layer are derived in this article. Based on the formulas, we have simulated quantum efficiency of Al x Ga1 − x N monolayer photocathode under different conditions. The results reveal that built‐in electric field caused by varying Al contents can significantly promote quantum efficiency of photocathode. If difference in Al contents between adjacent Al x Ga1 − x N monolayer enlarges, quantum efficiency will decrease. At the same time, built‐in electric field also plays a great impact in stabilizing quantum efficiency and photoelectric emission performance of Al x Ga1 − x N monolayer photocathode. The ideal quantum efficiency and photoelectric emission performance can be obtained when buffer layer thickness is about 50 to 75 nm. In addition, when emission layer is composed of a larger number of Al x Ga1 − x N monolayers with varying Al contents, the more number of monolayers with high Al contents are, the higher the quantum efficiency is. This study can give useful help for design and preparation of Al x Ga1 − x N monolayer photocathodes with varying Al contents. Abstract : To obtain high‐efficiency AlGaN monolayer photocathode, we present an Al x Ga1 − x N monolayer photocathode with varying Al contents and ultra‐thin emission layer. And then the quantum efficiency formulas of photocathode including reflection‐mode and transmission‐mode structures have been derived. From simulated results of quantum efficiency under different conditions, we can know that difference in Al components, thickness of Al x Ga1 − x N monolayer emission layer, thickness of buffer layer and Al components distribution have a crucial impact on improvement of quantum efficiency.