HgCdTe—CdTe异质结构的变频导纳特性

采用宽频带导纳测试系统研究了Ｈｇ０．６６Ｃｄ０．３４Ｔｅ－ＣｄＴｅ异质结构和Ａｌ－半绝缘ＣｄＴｅ－Ｈｇ０．６６Ｃｄ０．３４Ｔｅ结构样品的变频导纳特性，分析了不同结构样吕的测试结果，表明：异质结ＨｇＣｄＴｅ表面空穴积累，ＣｄＴｅ表面空穴耗尽，界面处的势垒使载流子局限于ＨｇＣｄＴｅ体内，样品的光伏响应光谱在２９７０ｃｍ＾－１和３６５０ｃｍ＾－１处各有一个响应峰，前者对应于界面ＨｇＣｄＴｅ的本征光伏效庆

VARIABLE FREQUENCY ADMITTANCE SPECTRA OF HgCdTe CdTe HETEROSTRUCTURE

Admittance voltage characteristics of Hg 0.66 Cd 0.34 Te CdTe heterostructures were studied by using a wide band admittance measurement system.HgCdTe heterostructures were grown by MBE technology.An energy band structure was established according to the analysis of C V and G V results.It was shown that,holes are accumulated at the HgCdTe surface while depleted at the CdTe surface and the barriers formed at the interface make the carriers confined in HgCdTe.The photovoltaic response spectrum shows two peaks,which are located at 2970cm -1 and 3650cm -1 respectively.The former peak is due to the intrinsic photovoltaic effect of HgCdTe,and the latter peak is due to the effect that holes in the accumulation layer are excited by photons and then overpass the hole barrier at the interface, i.e. ,the hole barrier height is about 0.41eV.