The multi-impurity system in CdSe nanoplatelets: electronic structure and thermodynamic properties

This paper theoretically studies the impurity states and the effects of impurity concentration and configuration on the optical, electrical, and statistical properties of CdSe nanoplatelets (NPLs). An image charge-based model of electron-impurity interaction is proposed. The charge-carrier energy spectra and corresponding wave functions depending on the impurity number and configuration are calculated. The electron binding energies are calculated for different NPL thicknesses. It is shown that the image charge-based interaction potential that arises due to the dielectric constants mismatch is much stronger than the interaction potential that does not take such a mismatch into account. Also, it is demonstrated that the binding energies are increasing with the number of impurities. We calculate the canonical partition function using the energy levels of the electron, which in turn is used to obtain the mean energy, heat capacity, and entropy of the non-interacting electron gas. The thermodynamic properties of the non-interacting electron gas that depend on the geometric parameters of the NPL, impurity number, configuration, and temperature are studied.