采用改进的垂直布里奇曼生长法生长Cd Zn Te(CZT)单晶,并在晶体生长后期采取长时间的原位恒温退火.采用红外透射显微镜、I-V特性曲线以及多道能谱仪测试经过原位退火后的晶体内部Te夹杂相分布、电阻率大小以及能谱响应.结果表明,原位退火可以大幅降低CZT晶体内部大尺寸Te夹杂相的密度,晶体内绝大部分的Te夹杂都集中在5μm以内.此外,原位退火后的晶体电阻率从4.54×108Ω·cm上升至3.73×1010Ω·cm.原位退火后的CZT晶体对241Am@59.5 ke Vγ射线表现出了良好的能量分辨率,为7.29%.
The growth interfaces of CdMnTe（CMT） crystals grown by traveling heater method（THM） were studied. Two types of polycrystalline CMT feed ingots synthesized in a traditional rocking furnace and vertical Bridgman（VB） furnace were adopted in THM growth, and the effects of the polycrystalline feed on the growth interface were revealed. The morphology of the growth interface of CMT crystal（CMT2） grown from the feed by vertical Bridgman was smoother with lower curvature compared with that of CMT crystal（CMT1） from the feed by rocking furnace. The radial Mn composition and Te inclusion distribution of the CMT wafers were analyzed and correlated to the growth interface. The Mn segregation along the radial direction and Te inclusion density of CMT2 were lower than those of CMT1. The VB method synthesized polycrystalline feed could improve the growth interface morphology, which is beneficial for decreasing the Te inclusions and Mn segregation in CMT wafers.
