利用红外(infrared, IR)显微镜、腐蚀坑形貌及傅里叶红外(Fourier transform infrared, FTIR)光谱仪观察研究溶液法制备CdZnTe晶体中的Te夹杂相. 讨论CdZnTe晶锭中Te夹杂相的分布和原因, 及其对晶体中位错密度(etch pit density, EPD) 和红外透过率的影响. 实验结果表明: 沿生长轴方向, Te 夹杂相密度增大, 相应的位错密度也增大; 红外透过率随Te 夹杂相密度的增大而减小, 生长末端晶体的透过率低至45%.
Te inclusions in CdZnTe crystals grown from solution has been investigated with transmission infrared (IR) microscopy, photography of etch pits and Fourier transform infrared (FTIR) transmission spectroscopy. Distribution and origination of Te inclusions in CdZnTe crystals are discussed, and the influence on the etch pit density (EPD) and IR transmittance are analyzed. The experimental results show that the density of Te inclusions increases along the growth direction, while the EPD increases. IR transmission decreases as the density of Te inclusions increases. The crystal in tail ingot has low transmittance of about 45%.
[1] Min J H, Chen J, Liang X Y, et al. Effects of gradient heat treatment on Te-rich CdZnTe crystal [J].Vacuum, 86(7): 994-997.
[2] Shin H Y, Sun C Y. Temperature-gradient-solution grown CdTe crystals for -ray detectors [J]. Journal of Crystal Growth, 1998, 186: 67-78.
[3] Limousin O. New trends in CdTe and CdZnTe detectors for X- and gamma-ray applications [J]. Nucl Instrument Methods Phys Res A, 2003, 504: 24-37.
[4] Min J H, Shi Z B, Qian Y B, et al. Simulation of the anode structure for capacitive Frisch grid CdZnTe detectors [J]. Nuclear Science and Techniques, 2009,
20(1): 46-50.
[5] Czock K H, Arlt R. Use of CdZnTe detectors to analyze gamma emission of safeguards samples in the field [J]. Nucl Instrument Methods Phys Res A, 2001,
458: 175-182.
[6] Fiederle M, Feltgen T, Meinhardt J, et al. State of the art of (Cd,Zn) Te as gamma detector [J]. Journal of Crystal Growth, 1999, 197: 635-640.
[7] Turjanska L, Hoschl P, Belas E, et al. Defect structure of CdZnTe [J]. Nucl Instrument Methods Phys Res A, 2001, 458: 90-95.
[8] Hu S Y, Henager C H, Jr. Phase-field simulations of Te-precipitate morphology and evolution kinetics in Terich CdTe crystals [J]. Journal of Crystal Growth, 2009,
311: 3184-3194.
[9] Min J H, Sang W B, Liu H T, et al. Improving the properties of CdZnTe crystals by annealing processes [J]. Rare Metal Materials and Engineering, 2007, 36(3): 471-474.
[10] 栾丽君,介万奇. 垂直布里奇曼法生长的Cd0.8Mn0.2Te单晶体中Te沉淀相分析[J]. 电子显微学报, 2009, 28(1): 57-61.
[11] 刘从峰,孙士文,方维政,等. 碲锌镉晶体第二相夹杂物特性研究[J]. 红外与激光工程, 2007, 36: 46-49.
[12] Hossain A, Xu L, Bolotnikov A E, et al. Distribution of Te inclusions in a CdZnTe wafer and their effects on the electrical properties of fabricated devices [J].
Nucl Instrument Methods Phys Res A, 2011, 652: 146-148.
