(中南大学 轻质高强结构材料重点实验室,长沙 410083)
摘 要: 碲锌镉(CZT)晶体被认为是目前最有前途的室温半导体探测器材料之一,因为其原子序数大、电阻率高、禁带宽度大,相较于传统材料探测器件具有能量分辨率高、体积小、便携等优点。目前,气相法、熔体法、溶液法等技术都被用来生长碲锌镉晶体。其中熔体法因生长系统简单可靠、速度快、晶体体积大等优点,已广泛应用于工业生产。但CZT低导热率、大蒸气压差异、低层错能等物理特性导致熔体法不可避免地会在晶体生长中引入空位、沉淀/夹杂相和位错等缺陷,严重影响其探测器的能量分辨率、响应速度等性能。本文对比了几种主流CZT晶体生长方法的优劣,总结了常见缺陷及改性的研究进展,并对CZT单晶生长及缺陷调控等未来研究方向进行了分析与展望。
关键字: 碲锌镉;熔体法;缺陷;单晶;半导体
(National Key Laboratory of Science and Technology on High-strength Structural Materials, Central South University, Changsha 410083, China)
Abstract:CdZnTe (CZT) detectors have been widely proposed and developed for room-temperature X-ray spectroscopy benefit from its excellent properties, and great efforts have been made on the crystal growth technologies. In last decades, melt growth method developed as most popular industrial method, since it requires simpler system, and growing faster and larger volume single crystal etc., compared to vapor transport method and solution growth method. On the other side, physical properties of CZT, such as low thermal conductivity, huge difference in vapor pressure, and low stacking fault energy etc., foster defects during the growth of crystal, like vacancies, precipitation, impurities, and dislocations. These defects restrain the performance of the detectors in terms of energy resolution and response speed. This paper compared the advantages and disadvantages between common growth methods, and summarizes the research on defects and annealing process. It might provide outlook on future in advancing the development of crystal growth and defects inhibition.
Key words: CdZnTe; melt growth; defects; single crystal; semiconductors