Abstract

During Stransky Kratsanov growth process, quantum dots with non-uniform shapes appear in a random way. Semi-prolate and oblate shapes are among the most likely nanostructures to be self-organized due to their dynamic stability on a substrate. It has been demonstrated that temperature and wetting layer play a very important role in this distribution. In these conditions, physical properties of the deposed semiconductor materials depend on the final structure obtained during the growth process. Si0.7Ge0.3/Si 0.7 Ge 0.3 / Si is a semiconductor mainly intended for the manufacture of optoelectronic detectors or in quantum transport. Thus it is important to understand their thermal properties such as heat capacity, entropy and Helmholtz energy. Finite Element Method is used in our calculation to solve numerically the Schr & ouml;dinger equation for a confined electron in semi- prolate and semi-oblate Si0.7Ge0.3/Si 0.7 Ge 0.3 / Si quantum dots. We have taken into account the size of the wetting layer thickness, the strain potential induced by lattice mismatch as well as the temperature. The energy spectrum is then used to determine the thermal characteristics using the statistical Boltzmann-Gibbs distribution. The internal energy of system, entropy, heat capacity, and Helmholtz free energy are determined as a function of the sizes of the quantum dots and wetting layer. The analysis of the behavior of thermodynamic properties presented in this study is considered as complementary and even necessary information to master for a good performance of optoelectronic devices.