The influence of local order at a crystal-melt interface on the AIIIBV crystal growth

An alternative approach to the study of crystallization process of the A(III)B(V) semiconductor compounds taking place at the "crystal-melt" interface has been considered in this paper. The influence of the short-range order in the interface region on the crystallization process has been studied at the atomic level. An elementary growth cell representing a system of five atoms, two of them are A(III) atoms belonging to a substrate, two other A atoms and the fifth B-V pertain to a solution-melt, has been proposed. Positions of the A(III) atoms belonging to the solution-melt are distributed in such a way that the resulting potential of the B-V atom proves to be double well. Transitions of the B-V atoms in such double-well potentials lead to crystallization. Taking the semiconductor compound GaP as an example, the potential energies of the pair interaction in the P-2, GaP and Ga-2 molecules are determined as functions of the interatomic distance. Based on these function dependences, the mean values of the double-well potential parameters are calculated. This allows to determine the mean rate of the elementary crystallization events at the interface. Some problems of the growing crystal morphology are discussed. (c) 2008 Elsevier B.V. All rights reserved.