Thermodynamic approach to the problem of A3B5 crystals with an optimum structural perfection

Thermodynamics of A³B⁵ semiconductor crystal, containing impurity and native point defects is considered. The main limit of the present analysis is the absence of a significant interaction between point defects at thermal equilibrium. It is shown that the difference of the chemical potentials of A³ and B⁵ components may serve as a structural sensitive thermodynamic function of a crystal. The optimization of the crystal perfection may be obtained when this function becomes zero. In the case of undoped A³B⁵ crystal such a situation corresponds to the ideal lattice perfection. In the case of doped crystal the effects of native point defects and their interaction with the impurity on the electronic properties of the crystal have to be reduced. The developed thermodynamic approach has been applied to the quantitative analysis of the available experimental data (GaAs, GaP, GaAs:Si and GaP:In). The results of the calculation are in reasonable agreement with the experiment.