DEVELOPMENT OF THE BASIC PROVISIONS OF THE THERMODYNAMIC MODEL OF QUASIBINARY SEMICONDUCTOR SOLID SOLUTIONS
The basic provisions of the thermodynamic model of semiconductor quasibinary solid solutions are presented. The model describes А3В5 and А2В6 semiconductor compounds with a sphalerite structure taking into account short-range correlations. The priority task is to calculate the internal energy and configurational entropy of the system. The determination of the excess values of these characteristics obtained by mixing the components of the solid solution is made. To solve this problem, a tetrahedron consisting of five atoms is selected as the main cluster. Five types of tetrahedral cells are introduced. Moreover, each tetrahedron is formed by five atoms – one central atom C and four atoms A or B at the vertices of the tetrahedron. Excessive internal energy due to the mixing of two binary components is described as the strain energy caused by local distortions of the crystal lattice. The probability of occurrence of each type of tetrahedron, as well as the configurational entropy caused by mixing, are determined using the quasi-chemical approximation.
Authors: I. A. Cheremukhina
Keywords: Solid solution, tetrahedron, excess internal energy, binding energy, configurational entropy, strain energy
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