The Modeling of Self-Consistent Electron-Deformation-Diffusion Effects in Thin Films with Lattice Parameter Mismatch

In our work, the model of self-consistent electron-deformation-diffusion effects in thin films grown on substrate with the mismatch of lattice parameters of the contacting materials is constructed. The proposed theory self-consistently takes into account the interaction of the elastic field (created by the mismatch of lattice parameters of the film and the substrate, and point defects) with the diffusion processes of point defects and the electron subsystem of semiconductor film. Within the framework of the developed model, the spatial distribution of deformation, concentration of defects, conduction electrons and electric field intensity is investigated, depending on the value of the mismatch, the type of defects, the average concentrations of point defects and conduction electrons. It is established that the coordinate dependence of deformation and the concentration profile of defects of the type of stretching (compression) centers, along the axis of growth of the strained film, have a non-monotonic character with minima (maxima), the positions of which are determined by the average concentration of point defects. It is shown that due to the electron-deformation interaction in film with a lattice parameter mismatch, the spatial redistribution of conduction electrons is observed and n-n+ transitions can occur. Information about the self-consistent spatial redistribution of point defects, electrons and deformation of the crystal lattice in semiconductor materials is necessary for understanding the problems of their stability and degradation of nano-optoelectronic devices operating under conditions of intense irradiation.

Automated summary

In this study, a model of self-consistent electron-deformation-diffusion effects in thin films grown on substrate with lattice parameter mismatch is constructed. The proposed theory considers the interaction between the elastic field and diffusion processes of point defects and the electron subsystem of the semiconductor film. The spatial distribution of deformation, defect concentration, conduction electrons, and electric field intensity is investigated within the developed model, depending on mismatch value, defect type, and average concentrations. It is found that the coordinate dependence of deformation and defect concentration of stretching (compression) centers in the strained film exhibit non-monotonic characteristics, determined by the average concentration of point defects. The study also shows that due to electron-deformation interaction, spatial redistribution of conduction electrons occurs with possible n-n+ transitions. Understanding the self-consistent spatial redistribution of point defects, electrons, and lattice deformation in semiconductor materials is important for the stability and degradation of nano-optoelectronic devices under intense irradiation.