Diamagnetic susceptibility and binding energy of hydrogenic impurity in CdSe nanoplatelets: Effect of dielectric mismatch and size-quantization

This study examines the binding energy and diamagnetic susceptibility of a hydrogen-like donor impurity in colloidal $CdSe$ nanoplatelets, taking into account polarization effects arising from the dielectric mismatch between the nanoplatelet and its surrounding medium. The adiabatic approximation and numerical methods are employed to solve the Schrödinger equation. The influence of impurity position, number of atomic monolayers, and environmental permittivity on impurity states is analyzed. The results reveal a non-monotonic dependence of the donor binding energy on impurity position and a strong sensitivity of the diamagnetic susceptibility to nanoplatelet thickness and dielectric mismatch. The behavior aligns with recent experimental trends observed for excitonic states in colloidal CdSe nanoplatelets. These insights provide valuable design guidelines for dielectric engineering and impurity control in optoelectronic applications.