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The unusual thermophysical properties of the CdZnTe crystals (high melt viscosity, a large latent heat of fusion, fairly
large equilibrium segregation coefficient, etc.) cause considerable difficulty in maintaining uniform zinc composition in
the grown crystal. The disadvantages can be overcome by the dewetted Bridgman technique in which the crystal is
grown detached from the ampoule wall by a liquid free surface at the level of the solid-liquid interface, called liquid
meniscus, which creates a gap between the grown crystal and the ampoule wall that bring together low contact stress
with low thermal stress. Crystal growth experiments showed that, in some conditions, chemical impurities at the liquid
surface may lead to unintended contamination that can increase the wetting angle artificially. This high sensitivity of the
wetting angle changes the meniscus shape, and hence the dopant distribution in the grown crystal.
For evaluating numerically the effect of the menisci shapes on the Zn distribution in CdZnTe crystals grown by dewetted
Bridgman technique, a pseudo quasi-steady state model is considered in the framework of a 2D axisymmetric geometry
containing two types of stable menisci: (i) a "S" shape meniscus that corresponds to the sum-of-the-angles criterion
αe+θc<180° (αe is growth angle and θc is wetting angle); (ii) a globally convex meniscus that corresponds to chemical
contamination, i.e., αe+θc>180°. Numerical computations including incompressible fluid flow in the Boussinesq
approximation, heat and mass transfer, and Marangoni effect, are performed using finite element technique. It is proven
that a convex meniscus assures the best impurity distribution.
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