坩埚内壁碳膜对Bridgman法生长CdZnTe晶体热应力的影响  

INFLUENCE OF THE GRAPHITE FILM PLATING ON THE INNER WALL OF QUARTZ CRUCIBLE ON THE THERMAL STRESS IN CdZnTe CRYSTAL PREPARED BY BRIDGMAN METHOD

作　　者：张国栋[1] 刘俊成[1] 李蛟[1] 

机构地区：[1]山东理工大学材料科学与工程学院,淄博255091

出　　处：《金属学报》2007年第10期1071-1076,共6页Acta Metallurgica Sinica

基　　金：国家自然科学基金项目50372036;教育部新世纪优秀人才支持计划项目NCET-04-0648资助

摘　　要：采用热弹性模型计算了垂直Bridgman(VB)法生长CdZnTe单晶体过程中的应力场,研究了坩埚内壁碳膜的厚度对晶体内热应力的影响.计算结果表明:晶体边缘与坩埚内壁接触位置的热应力远大于晶体中心处的热应力.晶体生长过程中存在两个高应力区:与坩埚接触的晶体底部与顶部(固/液界面下方)区,两个区的最大应力值在凝固过程中迅速增加,在随后的晶体冷却过程中较缓慢增大.增加碳膜厚度可以显著减小晶体边缘的热应力,然而对晶体中心的热应力影响较小.晶体生长完成85%左右时,用涂石墨坩埚生长的晶体比用石英坩埚生长的晶体的最大热应力小55%以上.The thermal stress field evolution during CdZnTe single crystal growth by using vertical Bridgman method was simulated with the thermal elastic model. The influence of the thickness of the graphite film plating on the inner wall of quartz crucible on the thermal stress was investigated. The results show that the thermal stress at the contact place between the edge of the crystal and the inner wall of quartz crucible is much larger than that in the center of the crystal. In addition, there are two maximal stress regions： the bottom of the crystal and the top below the liquid/solid interface. The maxium stress values increase rapidly during the solidification, and then increase slowly during cooling process. The increase of the graphite film thickness can decrease the thermal stress at the edge of the crystal obviously, but hardly affect the thermal stress in the center of the crystal. When the growth of the crystal achieved about 85%, the maximal thermal stress of the crystal grown with graphite coated crucible is less than 55% of that with pure quartz crucible.

关 键 词：CDZNTE 晶体生长 热应力场 数值模拟 

分 类 号：TN304.053[电子电信—物理电子学] O782[理学—晶体学]