Electron correlations in two dimensions: effects of finite thickness and image charges

Using the self-consistent STLS approximation of Singwi et al. we have studied the electron correlations in quasi-two-dimensional gas, surrounded by semi-infinite insulating media, including the effect of image charges (EICH) for different layer thickness and electron densities. By numerical self-consistent calculations of the plasmon dispersion, pair correlation function, structure factor, local-field corrections and correlation energy we have shown that for a certain region of electron density and layer thickness it is necessary to include both the correlation effects and the EICH in calculating physical properties of quasi-two-dimensional systems with significant differences between dielectric constants of neighboring media.