The Influence of Quantum Dot Size on Confinement Energy: A Modified Single Band Toy Model Approach

摘要

The influence of Quantum Dot Size on Confinement Energy was investigated using the modified single band toy model (MSBTM) approach with three different semiconductor quantum dots (QD) (Cadmium Selenide (CdSe), Zinc Sulphide (ZnS), and gallium Arsenide (GaAs)) considered. This was aimed at computing the emission and confinement energies of different sizes of the QD’s considered, and also comparing the degree of confinement of this study with other experimental works. It was observed that the sizes of semiconductor quantum dots considered are the same as the nano-size of the Bohr exciton radius of electron-hole pairs in solids. Due to this fact, they exhibit effects of quantum size as particles in a three dimensional box. The emission and confinement energies of electrons in semiconductor quantum dots considered increased exponentially with a decrease in the size of the nano-crystal. The graphs of the emission and confinement energies were plotted as a function of dot size for each of the three different semiconductor quantum dots. These exponential decay curves indicates that the lowest possible energy for a quantum dot sample is never zero as predicted using Brus equation.