以HgCdTe化合物的晶体生长为例,针对竖直Bridgman晶体生长过程,数值模拟了液相区界面处溶质分凝产生的溶质扩散边界层随拉晶速度和初始浓度的变化情况.结果表明:在拉晶速度从小变大的情况下,相变界面处溶质扩散受到抑制,浓度边界层变得越来越薄;当初始浓度不同时,分凝系数的变化决定了晶体生长过程中析出成分的多少,从而影响到液相区的溶质扩散情况,随着初始浓度的增大,溶质边界层有变薄的趋势,并且当初始浓度较大时这种趋势更为明显.
A numerical study is presented of the Bridgman crystal growth process of HgCdTe. Numerical results are reported for the effects of the pull rate and initial concentration on the solutal boundary layer near the interface. The results show that the solute diffusion will be restrained and the boundary layer becomes thin as the pull rate increases. Moreover, the variety of initial concentration lead to the change of segregate coefficient, which can affect the quantity of solute segregated during growth process and thus affect the solute diffusion. As a result, the solutal boundary layer is attenuated with the increase of initial concentration and this change is obvious when initial concentration is large.