Cd_(1-x)Zn_x合金组元分压控制下高阻CdZnTe晶体的熔体生长

CdZnTe Crystal of High Resistivity Melting Growth under Cd_(1-x)Zn_(x)Alloy Partial Pressures Control

本文运用热力学关系估算了ＣｄＺｎＴｅ 熔体平衡分压。尝试以Ｃｄ１ － ｘＺｎｘ 合金源替代Ｃｄ 源控制Ｃｄ 分压和Ｚｎ 分压进行了Ｃｄ０ ．８Ｚｎ ０ ．２Ｔｅ 晶体熔体生长，探讨了熔体分压与晶体电阻率的关系。获得的Ｃｄ０ ．８Ｚｎ ０ ．２Ｔｅ 晶体的电阻率接近１０１０Ω·ｃｍ ，高于同类方法文献报道１ ～２ 个数量级。晶体的结构完整性较好，平均腐蚀坑密度（ＥＰＤ） 为２ ×１０５ｃｍ － ２ ，纵向组成分布偏离度在４ ％ 左右，红外透过率大于６０ ％ ，晶体中第二相和沉淀物明显减少，优于仅采用Ｃｄ 分压控制的Ｃｄ０ ．８Ｚｎ０ ．２Ｔｅ 晶体。

Equilibrium partial pressures over CdZnTe melt have been estimated by thermodynamic relationship and Cd 0.8 Zn 0.2 Te crystal growth from the melt has been carried out under controlled Cd/Zn partial pressures,provided by Cd 1- x Zn x alloy source instead of Cd source.The relationship between partial pressures of the melt and the resistivity of crystal is discussed.The resistivity of Cd 0.8 Zn 0.2 Te crystal obtained reached up to about 10 10 Ω·cm,which is 1～2 of order higher than that reported in the literature using the same method.The structure perfection of as grown crystal is rather good.The mean EPD is about 2×10 5cm -2 .The variation in composition along the length of ingots is within 4%.The IR transmittance is larger than 60%.The second phases and precipitates in crystals are obviously decreased.The Cd 0.8 Zn 0.2 Te crystals are better than that obtained only under controlled Cd partial pressure.