Cd组分x对非晶态Hg_(1-x)Cd_xTe薄膜暗电导的影响  

Effect of Cd Composition on the Dark Conductivity of Amorphous Hg_(1-x)Cd_xTe Thin Films

作　　者：余连杰[1] 史衍丽[1] 苏玉辉[1] 李雄军[1] YU Lianjie SHI Yanli SU Yuhui LI Xiongjun(Kunming Institute of Physics, Kunming 650223, Chin)

机构地区：[1]昆明物理研究所,云南昆明650223

出　　处：《红外技术》2017年第1期32-35,共4页Infrared Technology

摘　　要：利用射频溅射方法制备了非晶态Hg_(1-x)Cd_xTe薄膜(x=0,0.22,0.50,0.66,1),在80 K^300 K温度范围内,研究了Cd组分x对暗电导的影响。当温度T>210 K时,随着Cd组分增加,暗电导减小;当温度T<210 K,随着Cd组分增加,则暗电导增大;当温度T=210 K时,暗电导几乎与Cd组分无关。这可能是由于随着Cd组分增加,薄膜中的缺陷增加所致。a-Hg_(1-x)Cd_xTe(x=0、0.22、0.50、0.66和1)薄膜中存在扩展态电导和局域态电导,Cd组分x越大,两种导电机制的转变温度Tm也越高。在T=300 K时,利用暗电导的激活能估算出了非晶态Hg_(1-x)Cd_xTe薄膜的迁移率隙Eg,随着Cd组分x增加,迁移率隙Eg微弱减小。The compositional dependence of electrical conductivity of amorphous Hg1-χCdχTe（χ=0, 0.22, 0.50, 0.66 and 1） thin films by RF sputtered technique in the range of 80 K^300 K is investigated. The results indicate that the dark conductivity decreases with Cd composition at high temperature range （T〉210 K）, increases with Cd composition at low temperature range （T〈210 K） and is independent of Cd composition at T=210 K. This is explained in terms of the increase in the density of defect states with increase of Cd composition in a-Hg1-χCdχTe thin films. There are two conduction mechanisms in the localized states and in the extended states for the a-Hg1-χCdχTe films. The transform temperature （Tin） from conduction in the localized states to conduction in the extended states will rise with increase of Cd composition. The mobility band gap Eg of a-Hg1-χCdχTe thin films is calculated as a function of Cd composition at T=300 K. The mobility band gap Eg of a- Hg1-χCdχTe thin films decreases tardily with the increase of Cd composition.

关 键 词：非晶态半导体 非晶态碲镉汞 暗电导 导电机制 

分 类 号：TN304.8[电子电信—物理电子学]