ACRT-Bridgman法制备组份均匀的碲锌镉单晶体

Preparartion of CdZnTe Single Crystal without Segregation with ACRT-Bridgman Method

采用加速坩埚旋转技术-Bridgman(ACRT-B)法制备了40mm的结构较为完整的Cd0.96Zn0.04Te晶锭.利用红外分光光度计测定晶片的近红外透射曲线,最大斜率切线法测定截止波长(cut-off wavelength,threshold wavelength),进而计算截止能量和该点的Zn组份。绘制了晶片表面的组织图,以及晶锭轴向剖面的Zn组份等高线图。实验结果表明:ACRT方法显著改善晶体组份的轴向偏析和径向偏析,晶锭中部存在两个Zn组份轴向和径向皆均匀的区域,分别约占晶锭体积的37%和16%,对应于两个大的单晶晶粒,大部分区域Zn组分径向偏析几乎完全消失。

A CdZnTe ingot was prepared with accelerated crucible rotation technique-Bridgman method （ACRT-B）. The infrared light transmission curves of the wafers were measured with FTIR, and the cut- off wavelength of each curve was determined by the tangent with the maximum slope. Therefore, the Zn solute concentration of one dot on the wafer could be calculated with its cut-off wavelength. The Zn solute distribution contour graph of the ingot longitudinal section was drawn. The surface structure of each wafer was also pictured. It shows that ACRT can improve both the radial solute segregation and the axial segregation in the ingot simultaneously. There are two sections without Zn segregation in the ingot, which account for 37%, 16% approximately of the whole ingot respectively, corresponding to two extra large single crystal grains in the axial position. ACRT makes the radial solute segregation in the majority of the ingot disappear completely.