Molecular Simulation study of the miscibility behaviour and microstructure of compound semiconductor alloys
The work under this topic envisions a molecular simulation study of the miscibility behaviour and the microstructure in compound semiconductor alloys. The Tersoff potential model is the interatomic interaction potential for the InxGa1-xAs alloy system, which is selected as a representative example of these alloys. The alloy will be modelled for a range of compositions (considering x from zero to unity) and temperature from 100 K to the measured upper critical solution temperature. The bulk phase and thin films are both considered in the study. The microstructure is characterized by properties such as lattice constant and bond length, which are useful to measure as a way to connect to experiment and thereby, validate the model. The local composition as predicted by simulations can help in predicting the effect of microphase segregation that is difficult to quantify experimentally. The existence of even small microphases can have a disproportionate effect on the optoelectronic properties of these alloys. Monte Carlo simulations in the isothermal-isobaric semigrand ensemble are used for simulation purposes. InxGa1-xAs has been chosen due to its special properties, which enable its extensive use in fibre optic communications. Though this work is modelling the InxGa1-xAs alloy system, it can be easily be extended to other III-V and II-VI compound semiconductor alloys.