A theoretical and experimental evaluation of III-nitride solar-blind UV photocathode

We have developed a superior solar-blind ultraviolet (UV) photocathode with an Al_xGa_1-xN photocathode (x ～ 0.45) in semi-transparent mode, and assessed spectra radiant sensitivity related to practical use. Before being grown over a basal plane sapphire substrate by low-pressure metal organic chemical vapor deposition (MOCVD), a reasonable design was made to the photocathode epitaxy structure, focusing on the Al_xGa_1-xN: Mg active layer, then followed by a comprehensive analysis of the structural and optical characterization. The spectra radiant sensitivity is peaked of 41.395 mA/W at wavelength 257 nm and then decreases by about 3 to 4 decades at 400 nm demonstrating the ability of this photocathode for solar-blind application prospects.     

HgCdTe阳极氧化膜及界面XPS分析

通过电子能谱仪对经阳极氧化表面钝化工艺处理的的ＨｇＣｄＴｅ表面所生成的氧化膜有界面进行深度分析研究，结果表明，该氧化膜中Ｔｅ和Ｃｄ的单质成分存在，氧化膜中的氧化物形式为ＴｅＯ２，ＣｄＴｅ２Ｏ５和ＨｇＴｅ２Ｏ５；在界面中，随着剖析深度的增加Ｔｅ２Ｏ＾２－５，向ＴｅＯ＾２－３过渡。