摘要
利用射频磁控溅射方法在宝石衬底上制备了非晶态碲化汞(HgTe)薄膜材料,以He-Ne激光器(hv=1.96 eV,λ=632.8 nm)作为激励光源,在80～300 K温度范围内,研究了非晶态HgTe薄膜的暗电导σd、稳态光电导σp以及光敏性σp/σd的特性,分析了载流子的导电和复合机制。实验发现,在80～300 K温度范围内,非晶态HgTe薄膜的暗电导和稳定态光电导均具有热激活特性。暗电导存在2个温区:在低温区(80 K≤T≤180 K),激活能约15 meV;在高温区(180 K<T≤300 K),激活能约400 meV。稳定态光电导则存在明显的3个温区:(1)当80 K≤T≤180 K时,光电导具有弱的热激活特性(激活能约20 meV);(2)当180 K<T≤280 K时,光电导具有强烈的热激活特性(激活能约120 meV);(3)当T>280 K时,光电导出现"热淬灭"效应。在温度约280 K时,光电导具有最大值,而光敏性则在约180 K时具有最大值。非晶态HgTe薄膜中存在两种导电机制:定域态电导和扩展态电导,180 K两种导电机制的温度分界点。研究结果表明,非晶态HgTe薄膜很适合制备高工作温度(约180 K)红外探测器。
The amorphous HgTe films were prepared by the RF magnetron sputtering technique onto quartz substrates.The source of light is a He-Ne Laser（hv=1.96 eV,？=632.8 nm）.The dark conductivity（？d）,steady state photoconductivity（？p）,and photosensitivity（？p/？d） of amorphous HgTe films were investigated in the range of 80～300 K temperatures.Both ？d and？p of amorphous HgTe films are thermally activated in the 80～300 K temperature range.Two temperature regions have been observed in temperature dependence of dark conductivity of amorphous HgTe films： in the range of the low temperature（80 K≤T≤180 K）,？d is poorly activated with T（activation energy ～15 meV）,and in the range of high temperature（180 KT≤300 K）,？d is strongly thermally activated with activation energies ～400 meV.The measurement of ？p as a function of T indicates the presence of three distinct regions：（1） For 80 K≤T≤180 K,？p is poorly activated with T（activation energy ～20 meV）,（2） for 180 KT≤280 K,？p is thermally activated with activation energies ～120meV,and（3） for T280 K,a thermal quenching（TQ） of ？p is measured in all the amorphous HgTe films.A maximum in photoconductivity is observed at a particular temperature（～280 K） while the maximum of the photosensitivity is at ～180 K.Two conduction mechanisms were obtained in the amorphous HgTe films： conduction in the located states and conduction in the extended states.180 K is the transform temperature of two conduction mechanisms.The results of the paper indicate that the amorphous HgTe films will be promising materials for many applications in infrared detectors operating at high temperature（～180 K）.
出处
《红外技术》
CSCD
北大核心
2011年第4期190-194,共5页
Infrared Technology
基金
云南省基金面上项目
关键词
非晶态碲化汞
光电导
暗电导
热激活
热淬灭
Amorphous HgTe
photoconductivity
dark conductivity
thermally activated
thermal Quenching
