硅酸盐学报

采用多步骤组合退火方法改善碲镁镉晶体的性能

PDF下载

张嘉伟 ¹ , 俞鹏飞 ¹ , 韩召 ¹ , 杨桂芝 ¹ , 介万奇 ²

硅酸盐学报 | 研究论文 2025,53(1): 102-113

收起

硅酸盐学报 |研究论文 2025 , 53 (1) : 102 -113

采用多步骤组合退火方法改善碲镁镉晶体的性能

全屏

张嘉伟¹, 俞鹏飞¹, 韩召¹, 杨桂芝¹, 介万奇²

作者信息

^1．长安大学材料科学与工程学院，西安 710064

^2．西北工业大学，凝固技术国家重点实验室，西安 710072

通讯作者:

俞鹏飞（1982—），男，博士，副教授。

作者简介:

张嘉伟（2001—），男，硕士研究生。

Enhanced Properties of CdMgTe Crystals by Multi-Step Annealing Method

Jiawei ZHANG¹, Pengfei YU¹, Zhao HAN¹, Guizhi YANG¹, Wanqi JIE²

Affiliations

^1.School of Materials Science and Engineering, Changʹan University, Xiʹan 710064, China

^2.State Key Laboratory of Solidification Processing, Northwestern Polytechnical University, Xiʹan 710072, China

Corresponding Author:

YU Pengfei (1982-), male, Ph.D., Associate Professor. E-mail: yupengfei@chd.edu.cn

ZHANG Jiawei (2001-), male, Master candidate. E-mail: 2023131003@chd.edu.cn

出版时间: 2025-01-20 doi: 10.14062/j.issn.0454-5648.20240438

文章导航

摘要

收起

碲镁镉（CdMgTe）晶体是一种理想的室温辐射探测新材料，但生长态晶体中仍然存在较多的缺陷，降低了探测器性能。采用多步骤组合退火方法对CdMgTe晶体进行退火改性，探讨了退火温度对晶体缺陷、力学、光学和电学性能的影响。结果表明，Cd气氛退火后晶体中的Te夹杂相大幅减少，红外透过率和电阻率明显下降，经Te气氛退火后Te夹杂相密度无明显变化，而红外透过率和电阻率则显著提高且优于生长态晶体。退火后，晶体表面未出现额外氧化，禁带宽度最大增加了0.021 eV，显微硬度最多提高了16%，Raman光谱测试表明晶体中出现了新缺陷，探测器性能出现了质的变化。最佳退火条件获得的CdMgTe晶体制作的平面探测器性能最好，电子迁移率达526.86 cm²/（V·s），能量分辨率和电子迁移率寿命积分别为15.6%和1.89×10^-4 cm²/V。

关键词

碲镁镉晶体 / 多步骤组合退火 / 晶体质量 / 电阻率 / 室温辐射探测器

Abstract

收起

Introduction

Cadmium magnesium telluride (CdMgTe) crystal is an ideal material for room-temperature radiation detection. However, there are still many defects in as-grown crystals, which degrade the detector performance. At present, a single annealing method is unable to achieve the effect of both eliminating defects and maintaining or increasing resistivity. The multi-step combined annealing method can improve the crystal quality and the detector performance. There are a few studies on the annealing of CdMgTe crystals. In this work, a multi-step combined annealing method was used, i.e., the CdMgTe crystals grown under Te-rich condition were annealed in Cd atmosphere and Te atmosphere. The effect of annealing temperature on the defects, mechanics, photoelectric properties and detector performance of CdMgTe crystals was investigated.

Methods

High purity (7N) cadmium (Cd) and tellurium (Te) were selected as raw materials. The selected slices for annealing were derived from In-doped Cd_0.95Mg_0.05Te ingot grown by a modified vertical Bridgman method under Te rich condition, with the size of 5 mm×5 mm×2 mm. The annealing in Cd atmosphere was mainly divided into two steps, i.e., high and low temperature annealing. In the high temperature annealing step, the temperatures of the slices were 873, 923 K and 973 K, respectively. The corresponding temperatures of Cd source were 901, 946 K and 986 K, respectively. The annealing time was 120 h. After high temperature annealing, the temperature of the slices and Cd source reduced to 623 K, and the annealing time was also 120 h. After annealing in Cd atmosphere, it continued annealing in Te atmosphere. The annealing temperature of both slices and Te source was selected to 773 K, and the annealing time was also 120 h.

The CdMgTe crystals before and after annealing were characterized by infrared transmission microscopy, scanning electron microscopy, ultraviolet-visible-near infrared (NIR) spectroscopy, infrared transmittance spectroscopy, Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), Vickers indentation analysis and current-voltage (I-V) measurement. Au/CdMgTe/Au planar detectors were fabricated by an evaporation method, and the energy spectrum was collected in ORTEC test system. The radiation source was ²⁴¹Am α particle source with a non-collimated energy of 5.48 MeV.

Results and discussion

The band gap of the as-grown crystal is 1.510 eV, and the maximum band gap is increased by 0.021 eV after annealing. After annealing in Cd atmosphere, Te inclusions in the crystals are greatly reduced. At the annealing temperature of 973 K, Te inclusions can be completely eliminated. The IR transmittance and resistivity are reduced. The density of Te inclusions has little change after annealing in Te atmosphere. However, the IR transmittance and resistivity improve and are better than those of the as-grown crystals. The optimum IR transmittance and resistivity are 63% and 2.41×10¹⁰ Ω·cm, respectively. After multi-step combined annealing, there is no extra oxidation on the crystal surface, and the microhardness is increased by 16%. The Raman spectra show that the crystal quality is improved.

Au/CdMgTe/Au planar room temperature radiation detectors are fabricated with the crystals obtained under the optimum annealing conditions. The time-of-flight (TOF) measurements show a significant increase in electron mobility, up to 526.86 cm²/(V·s). The optimum energy resolution and electron mobility lifetime product of the detector are 15.6% and 1.89×10^-4 cm²/V, respectively, using ²⁴¹Am α particles with an energy of 5.48 MeV as a radiation source.

Conclusions

CdMgTe crystals were annealed by a multi-step combined method. After annealing, there was no additional oxidation on the crystal surface, and Te inclusions decreased significantly. The band gap, microhardness, IR transmittance and resistivity of the crystals were all improved, indicating the improvement of crystal quality. The optimum annealing conditions were in Cd atmosphere at high (i.e., 923 K) and low (623 K) temperatures for 120 h, and then in Te atmosphere at a low (i.e., 623 K) temperature for 120 h. The optimum performance of CdMgTe detector was electron mobility (μ_e) of 526.86 cm²/(V·s), the energy resolution of 15.6%, and the mobility lifetime product (μ_τ)_e of 1.89×10^-4 cm²/V.

Key words

cadmium magnesium telluride crystal / multi-step combined annealing / crystal quality / resistivity / room temperature radiation detector

引用本文

张嘉伟, 俞鹏飞, 韩召, 杨桂芝, 介万奇. 采用多步骤组合退火方法改善碲镁镉晶体的性能. 硅酸盐学报, 2025 , 53 (1) : 102 -113 . DOI: 10.14062/j.issn.0454-5648.20240438

Jiawei ZHANG, Pengfei YU, Zhao HAN, Guizhi YANG, Wanqi JIE. Enhanced Properties of CdMgTe Crystals by Multi-Step Annealing Method[J]. Journal of the Chinese Ceramic Society, 2025 , 53 (1) : 102 -113 . DOI: 10.14062/j.issn.0454-5648.20240438

基金

收起

西北工业大学凝固技术国家重点实验室开放课题(SKLSP202318)
陕西省重点研发计划项目(2022GY-358)

参考文献

收起

文献

收起

参考文献引证文献

排序方式：

2025年第53卷第1期

PDF下载

引用本文

BibTeX

文章信息

doi: 10.14062/j.issn.0454-5648.20240438

接收时间：2024-07-02
首发时间：2026-10-22
出版时间：2025-01-20

补充材料

相关文章

文章信息

作者

出版历史

收稿日期：2024-07-02
修回日期：2024-07-10

基金

西北工业大学凝固技术国家重点实验室开放课题(SKLSP202318)

陕西省重点研发计划项目(2022GY-358)

作者信息

^1．长安大学材料科学与工程学院，西安 710064

^2．西北工业大学，凝固技术国家重点实验室，西安 710072

通讯作者:

俞鹏飞（1982—），男，博士，副教授。

参考文献

分享链接

https://castjournals.cast.org.cn/joweb/gsyxb/CN/10.14062/j.issn.0454-5648.20240438

分享至

全文二维码

扫描看全文

引用本文

BibTeX

本文的引用情况

2种不同金属材料的力学参数

科 Family	属数 Number of genus	种数 Number of species	占总种数比例 Percentage of total species (%)	属 Genus	种数 Number of species	占总种数比例 Percentage of total species (%)
鹅膏菌科Amanitaceae	2	11	5.26	鹅膏菌属 Amanita	10	4.78
小菇科 Mycenaceae	2	12	5.74	丝盖伞属 Inocybe	5	2.39
多孔菌科 Polyporaceae	8	14	6.70	蜡蘑属 Laccaria	5	2.39
红菇科 Russulaceae	3	23	11.00	小皮伞属 Marasmius	6	2.87
				小菇属 Mycena	11	5.26
				光柄菇属 Pluteus	5	2.39
				红菇属 Russula	17	8.13
				栓菌属 Trametes	5	2.39

关闭全屏

BibTeX
EndNote
RefWorks
TxT