原位热处理对碲锌镉晶体质量和性能的影响

摘要/Abstract

摘要： Te夹杂是碲锌镉(CdZnTe, CZT)晶体中的一种常见缺陷。本研究旨在通过改进移动加热器法(THM)生长CZT晶体的工艺参数和设计原位热处理方案,以减少晶体中Te夹杂的数量和尺寸,从而优化CZT晶体的质量和性能。综合考虑了晶体生长速度、生长温度、富Te料的配比及温场之间的相互影响,对工艺参数进行了优化。研究基于Te在不同温度下的溶解度差异,选择800 ℃作为CZT晶体的生长温度,设计了高温溶解-低温脱溶的原位热处理方案,在860 ℃下进行长时间恒温退火,以最大限度地吸收Te夹杂,并采用快速降温以减小大尺寸Te夹杂的数量。结果显示,相较于未经过原位热处理的CZT晶体,经过原位热处理的CZT晶体大尺寸Te夹杂显著减少,小尺寸Te夹杂的浓度有所增加,杂质缺陷和Te间隙(Te_i)减少,但Te反位(Te²⁺_Cd)浓度有所增加。电流-电压特性测试和能谱响应测试结果表明,经原位热处理的CZT晶体具有较高的电阻率和更优的能量分辨率。

关键词: 碲锌镉, 移动加热器法, 晶体生长, 原位热处理, Te夹杂

Abstract: Te inclusions are common defects in cadmium zinc telluride (CdZnTe, CZT) crystals. The objective of this study is to optimize the quality and properties of CZT crystals by improving the process parameters for growing CZT crystal by traveling heater method (THM) and designing an in-situ heating treatment to reduce the quantity and size of Te inclusions. The process parameters were optimized by considering the interactions between the crystal growth rate and temperature, the ratio of Te-rich materials and the temperature field. Based on the different solubilities of Te at different temperatures, this study selected 800 ℃ as the growth temperature and devised an in-situ heating treatment scheme comprising high-temperature dissolution and low-temperature desolvation. This scheme was designed to enhance the absorption of Te inclusions by a long annealing time at 860 ℃ and to reduce the number of large-size Te inclusions by a rapid temperature reduction. The results demonstrate that CdZnTe crystals subjected to in-situ heating treatment exhibit a notable reduction in the concentration of large-size Te inclusions, an increase in the concentration of small-size Te inclusions, a reduction in impurity defects and Te_i, and an increase in the concentration of Te²⁺_Cd. The current-voltage characterisation tests and energy spectral response tests show that the in-situ heating treated CdZnTe crystals exhibit higher resistivity and superior energy resolution.

Key words: CdZnTe, traveling heater method, crystal growth, in-situ heating treatment, Te inclusion

中图分类号:

O786

王坤元, 梁小燕, 闵嘉华, 张继军. 原位热处理对碲锌镉晶体质量和性能的影响[J]. 人工晶体学报, 2024, 53(12): 2079-2084.

WANG Kunyuan, LIANG Xiaoyan, MIN Jiahua, ZHANG Jijun. Effect of In-Situ Heating Treatment on the Quality and Properties of CdZnTe Crystals[J]. JOURNAL OF SYNTHETIC CRYSTALS, 2024, 53(12): 2079-2084.

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