Electronic structure and transport properties of coupled CdS/ZnSe quantum dots

TL;DR

This study investigates the electronic structure and transport properties of coupled CdS/ZnSe quantum dots, revealing asymmetric transport behavior and potential for tunable switching applications.

Contribution

It provides a detailed analysis of how coupling strength affects electronic transport and rectification in coupled quantum dots, which was not previously explored.

Findings

Asymmetric current-voltage characteristics observed.

Transport properties can be tuned by coupling strength.

Potential for rectification and switching in quantum dot devices.

Abstract

Electronic structure and transport characteristics of coupled CdS and ZnSe quantum dots are studied using density functional theory and non equilibrium Greens function method respectively. Our investigations show that in these novel coupled dots, the frontier occupied and unoccupied molecular orbitals are spatially located in two different parts of the coupled dot, thereby indicating the possibility of asymmetry in electronic transport. We have calculated electronic transport through the coupled quantum dot by varying the coupling strength between the individual quantum dots in the limits of weak and strong coupling. Calculations reveal asymmetric current vs voltage curves in both the limits indicating the rectifying properties of the coupled quantum dots. Additionally we discuss the possibility to tune the switching behavior of the coupled dots by different gate geometries.