温度梯度溶液生长法制备x=0.2的Cd_(1-x)Zn_xTe晶体及性能研究

Growth and characterization of Cd_(1-x)Zn_xTe(x=0.2) crystals by temperature gradient solution growth

利用温度梯度溶液生长法(TGSG)在较低生长温度下制备了掺Al和掺In的x=0.2的Cd1-xZnxTe晶体,晶体起始生长温度约为1223K,温度梯度为20～30K/cm,坩埚的下降速度为1mm/h。采用红外显微镜、傅里叶红外光谱仪、扫描电镜能谱仪(SEM/EDS)和I-V测试分别研究了晶体中的Te夹杂相、红外透过率、Zn组分分布和电阻率。结果显示CdZnTe晶锭初始生长区、稳定生长区的Te夹杂相密度分别为8.3×103、9.2×103/cm-2,比垂直布里奇曼法生长的晶体低约1个数量级,红外透过率分别为61%、60%。Al掺杂CdZnTe晶体的电阻率为1.05×106Ω.cm,而In掺杂CdZnTe晶体的电阻率为7.85×109Ω.cm。晶锭初始生长区和稳定生长区的Zn组分径向分布均匀。

Cd1-xZnxTe（x=0. 2） bulk crystals with the AI dopant and In dopant had been growth by the tempera- ture gradient solution growth （TGSG） with the lower starting growth temperature of 1223K, temperature gradi- ent of 20-30 K/cm and growth rate of lmm/h. IR microscopy,FTIR transmission spectroscopy, SEM/EDS and I-V characteristics were adopted to analyze the Te inclusions,IR transmittance, Zn component distribution and resistivity of the crystals,respectively. The results showed that the density of Te inclusions in the first-to-freeze and stable growth of the ingots were 8.3 × 10^3 , 9.2 × 10^3/cm^-2 respectively,which were about 1 magnitude order lower than that of ingots grown by the vertical Bridgman growth, while the corresponding IR transmittance of the ingots were 61% ,60%. The resistivity of the A1 doped CdZnTe crystal was 1.05× 10^6 Ω·cm, while the re- sistivity of the In doped CdZnTe was 7.85 × 10^9 Ω·cm. In addition, the radial distribution of the Zn component was uniform in the first-to-freeze and stable Rrowth of the ingots.