Modulating Pseudo Confinement in Type-II Core-Shell Quantum Dots

Abstract

We investigated the transition energy modulation in type-II core-shell quantum dots (CSQDs) using a single-band step-potential framework. By analyzing radial probability densities and quantum transmission coefficients, we classify carrier confinement regimes as strong or weak based on potential barriers and localization behavior. Applied to PbS/CdS and ZnTe/ZnSe heterostructures, our model reveals that strong confinement enhances transition energies via suppressed tunneling and sharp wavefunction localization. In contrast, weak confinement allows partial delocalization, leading to a step-defined pseudo-type-II regime where hole behavior exhibit type-I-like hole localization despite type-II band alignment. These findings provide theoretical insight into tuning near-infrared transition energies and carrier lifetimes for quantum dot optoelectronic applications.