碲锌镉晶体VGF法生长温场的梯度区高度设计研究北大核心CSCD

本文对不同梯度区高度的VGF法温场生长碲锌镉(CdZnTe)晶体过程进行了稳态和非稳态仿真模拟分析。研究发现,晶体生长等径初期界面凸度随着梯度区高度的增加而减小;等径末期界面凸度受梯度区高度的影响不大;界面的凸度与固液界面温度梯度变化率正相关。非稳态模拟结果显示,现有变温条件下,晶体生长过程中固液界面凸度存在先增大后减小的趋势,趋势转变点接近梯度区高度中点;界面形状的变化趋势受固液界面上生长速度分布直接影响;对比而言,10 cm高的梯度区更容易实现前中期固液界面凸界面的获得,利于形成高单晶率CdZnTe晶体。

Study on the design of gradient zone height for verticalgradient freeze growth of CdZnTe crystal

In this paper,different gradient zone height designs for vertical gradient freeze growth of CdZnTe crystal are researched by steady and unsteady computational model.It is found that the solid/liquid interface convexity decreases with the increase of gradient zone height at the initial stage of the crystal growth,and the interfacial convexity at the end of isometry is not greatly influenced by the gradient zone height.Also,there is a positive correlation between the solid/liquid interface convexity and the change rate of axial temperature gradient.Unsteady computational results present that the solid/liquid interface convexity increases at first and then decrease.The position of the trends change point is close to the middle height of gradient zone.The trends change of solid/liquid interface convexity is directly influenced by the distribution of growth rates at the solid/liquid interface.In contrast,gradient zone with 10cm height is easiest to achieve the convex interface in the early and middle crystal growth stage,which is conductive to the formation of CdZnTe single crystal.