移动加热器法生长CdMnTe晶体的性能研究  

Study on the Properties of CdMnTe Crystals Grown by Traveling Heater Method

作　　者：沈萍[1] 张继军[1] 王林军[1] 沈敏[1] 梁巍[1] 孟华[1] 

机构地区：[1]上海大学材料科学与工程学院,上海200444

出　　处：《人工晶体学报》2014年第1期13-18,共6页Journal of Synthetic Crystals

基　　金：国家自然科学基金(11375112;11275122);上海市科委重点项目(11530500200);上海市教育委员会科研创新项目(12ZZ096)

摘　　要：采用垂直布里奇曼法（VB）生长CdMnTe晶体，由于生长温度高、堆垛层错能低、热应力大等因素，晶体中存在大量孪晶、杂质、夹杂相等，限制其在核辐射探测器方面的应用。为了提高晶体的质量，本文采用移动加热器法（travelling heater method，THM）生长CdMnTe晶体，对该方法生长的晶体中Mn的轴向分布、杂质浓度、Te夹杂和电学性能进行测试分析，并与VB法生长的晶体作对比。结果表明THM法生长的CdMnTe晶体中Mn的轴向分布均匀，杂质浓度低于VB法制得的晶体，Te夹杂的尺寸5～25μm，浓度10^3cm^-3，电阻率为10^9-10^10Ω·cm，导电类型为弱n型，制备的探测器在室温下对蝴Am放射源有能谱响应。实验表明THM法生长的CMT晶体在晶体质量和电学性能方面明显优于VB法。CdMnTe crystals grown by vertical bridgman method contain lots of twins, impurities and inclusions, due to its high growth temperature, low stacking fault and high thermal stress, which hinders its application in nuclear radiation detectors. In this paper, the CdMnTe crystal was grown by travelling heater method （THM） in order to improve its crystal quality, and compared with the crystal grown by vertical bridgman （VB） method on the Mn axial distribution, impurity concentrations, Te inclusions and electrical properties. The results showed that the CdMnTe crystal grown by the THM had more uniform Mn distribution and lower impurity concentrations compared to the crystal grown by VB method. The size of Te inclusion in the crystal grown by THM was 5-25 μm with the concentration of 105 cm -3, and the resistivity were in the range of 10^9-10^10Ω·cm with the conductivity of weak n-type. The energy response spectroscopy of CdMnTe detector fabricated on the crystals grown by THM was revealed under 24t Am radiation at room temperature. The results demonstrate that CdMnTe crystals grown by THM have better crystal quality and electrical properties compared to that by VB method.

关 键 词：CDMNTE 移动加热器法 垂直布里奇曼法 Te夹杂 电学性能 

分 类 号：O78[理学—晶体学]