Two important phenomena of ‘‘quantum tunneling’’ and ‘‘self-energy’’ are particularly important in nanocomposites, because tunneling of electrons or holes through the ultra-thin dielectric barrier and excluding the screening of these carriers can cause the loss of control over current passing through these nanocomposites. Here, due to great density of carriers that are seen as condensed quantum dots, the system is regarded as a many-body system with quantum dots interaction, and the self-energy equation is obtained using Green’s function equations, screening, polarization, and dielectric constant related to aluminum oxide (Al2O3) and poly vinyl phenol nanocomposites. Also, according to the current density verse applied voltage (I–V) and non-uniform structures of the samples, the equation for the current density of the quantum tunneling is achieved.