碲锌镉晶体生长温度梯度与界面形状稳定性关系的研究

摘要/Abstract

摘要： 碲锌镉晶体被广泛用作红外探测器碲镉汞薄膜的外延衬底和制造室温核辐射探测器。在晶体生长过程中,界面形状与热量传输状态密切相关。本文结合数值模拟技术控制碲锌镉晶体生长过程中温度场分布,设计了垂直布里奇曼法和垂直温度梯度凝固法微凸固液界面的晶体生长程序,并根据实际晶体生长实验,分析了晶体生长方法差异与碲锌镉晶体单晶率之间的关系。通过光致发光谱进行成分测试获得了碲锌镉晶体等径段纵截面中Zn值分布谱图,以研究固液界面温度场分布与晶体Zn值宏观偏析之间的关系。结果表明,在晶体生长过程中固液界面两侧温场梯度分布对界面的形状选择和稳定性有重要影响,更大的固相侧温度梯度有助于实现稳定的凸界面晶体生长,从而提高晶体成晶率。

关键词: 碲锌镉晶体, 数值模拟, 晶体生长, 界面形状, 界面稳定性, 宏观偏析

Abstract: CdZnTe crystals are widely used as epitaxial substrates for HgCdTe thin films for infrared detectors and in the fabrication of room temperature nuclear radiation detectors. During crystal growth, the interface shape is closely related to the heat state. Combined with the numerical simulation technique to control the temperature field distribution during CdZnTe crystal growth, the crystal growth procedure of micro-convex solidification interface by vertical Bridgman method and vertical gradient freeze method were designed, and the single crystal rate of CdZnTe crystals was analyzed according to the actual crystal growth experiments. The distribution spectrum of Zn components in the longitudinal section of CdZnTe crystals with equal diameters was obtained by photoluminescence spectroscopy for compositional testing in order to investigate the relationship between the temperature field distribution at the solid-liquid interface and the macroscopic segregation behavior of Zn components. It is found that the temperature gradient distribution on both sides of the solid-liquid interface significantly influences the shape selection and stability of the solidification interface during the crystal growth process, and a larger temperature gradient on the solid-phase side contributes helps to achieve stable crystal growth at the convex interface, thereby increasing the likelihood of growing single crystals.

Key words: CZT crystal, numerical modeling, crystal growth, interface shape, interface stability, macro-segregation

中图分类号:

曹聪, 刘江高, 范叶霞, 李振兴, 周振奇, 马启司, 牛佳佳. 碲锌镉晶体生长温度梯度与界面形状稳定性关系的研究[J]. 人工晶体学报, 2024, 53(4): 641-648.

CAO Cong, LIU Jianggao, FAN Yexia, LI Zhenxing, ZHOU Zhenqi, MA Qisi, NIU Jiajia. Relationship Between Temperature Gradient and Interfacial Shape Stability of CZT Crystal Growth[J]. JOURNAL OF SYNTHETIC CRYSTALS, 2024, 53(4): 641-648.

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