As掺杂碲镉汞多载流子体系电学特性研究

Study of electricproperties for As-doped Hg_(1-x)Cd_xTe multi-carrier system

用液相外延（LPE）方法在CdZnTe衬底上生长了厚度为14.19μm的Hg1-xCdxTe样品。在Hg1-xCdxTe中进行As掺杂,获得低温下的p型导电材料。对As掺杂Hg1-xCdxTe样品进行了磁输运测试,获得磁电阻和Hall电阻在不同温度下随磁场的变化曲线。用最大熵原理迁移率谱结合多载流子拟合（MEPMS＋MCF）的分析方法,获得样品中参与导电的载流子种类,以及每种载流子浓度和迁移率随温度的变化。结果表明,在20~280 K的温度范围,空穴的浓度开始随温度的升高不断增加,到100 K后,空穴的浓度随温度的升高逐渐减小。其迁移率在低温区随温度的升高逐渐减小,到100 K后,迁移率随温度的升高逐渐增加。在100~280 K的温度范围,本征激发的电子开始参与导电,其浓度随温度的升高不断增加,迁移率随温度的升高不断减小。用MEPMS＋MCF分析方法获得的零场电阻与实验结果很好符合。

The Hg1-xCdxTe sample with the thickness of 14.19 μm was grown on CdZnTe substrate by liquid phase epitaxy（LPE）.The sample was doped with As atoms to achieve p type semiconductor at low temperature.The magneto-resistance and Hall resistance as a function of magnetic field at different temperature for this sample have been observed by means of magneto-transport measurements.The carrier species,as well as the concentration and mobility of each species as a function of temperature,was obtained by using the hybrid approach combining maximum entropy principle mobility spectrum（MEPMS） and multi-carrier fitting（MCF） methods.The hole concentration increases with the increase of temperature in low temperature range,and decreases with increasing temperature when the temperature is above 100 K.The intrinsic electron gives important contribution to conductance in the temperature range of 100～280 K.The electron concentration increases with the increase of temperature.And the electron mobility decreases with the increase of temperature.The calculated zero-field resistance achieved by using the hybrid approach is consistent well with the one obtained by experiment.