坩埚中自由空间量对Bridgman法生长的CdZnTe晶体缺陷的影响  

Influence of Free-space Volume in Ampoule on Defects of CdZnTe Crystal Grown by Bridgman Method

作　　者：李辉[1] 闵嘉华[1] 王林军[1] 夏义本[1] 张继军[1] 叶邦角[2] 

机构地区：[1]上海大学材料科学与工程学院,上海200072 [2]中国科学技术大学物理学院,合肥230022

出　　处：《无机材料学报》2012年第8期790-794,共5页Journal of Inorganic Materials

基　　金：国家自然科学基金(10675080);上海市重点学科基金(S30107)~~

摘　　要：采用Bridgman法生长CdZnTe晶体.分别采用红外透过显微镜和正电子湮灭寿命谱仪研究了CdZnTe晶体中的Te夹杂相、Cd空位等缺陷与坩埚中的自由空间量大小的关系.结果表明:随着坩埚自由空间量的减小,晶体中Te夹杂相密度从6.67×104/cm2降低到2.36×103/cm2,且Te夹杂相尺寸减小;晶体的正电子平均寿命值随着坩埚自由空间量的减小从325.4 ps降低到323.4 ps,表明晶体的Cd空位浓度及微结构缺陷减少;晶体的红外透过率和电阻率则随着坩埚自由空间量的减小大幅提高,进一步表明坩埚中自由空间量的减小能够有效地降低晶体中的缺陷浓度.CdZnTe crystal was grown by Bridgman method.The relationship between the free-space volume in the ampoule and the defects in CZT,such as Te inclusion and Cd vacancy,was studied by IR transmission microscopy and positron annihilation technique（PAT）.With the decrease of the free-space volume in the ampoule,the density reduced from 6.67×104/cm2 to 2.36×103/cm2 with the reduction of Te inclusions.The average positron lifetime decreased from 325.4 ps to 323.4 ps with the decrease of the free-space volume,indicating a reduction of Cd vacancies.The improvement of IR transmittance and resistivity of CZT further demonstrates that lowing the free-space volume in the ampoule can effectively depress the defects in CZT crystal.

关 键 词：CDZNTE 缺陷 正电子寿命 Te夹杂 

分 类 号：O77[理学—晶体学]