Influence of the graphite film plating on the inner wall of quartz crucible on the thermal stress in CdZnTe crystal prepared by bridgman method

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.