Unveiling Role of Size, Wet Layer Thickness, and Interface Potential Barrier on the Confinement Effect of the Conical, Cylindrical and Spherical Quantum Dots

This research work presents an impact on the energy states and probability density of finding electrons due to the confinement of different size parameters such as quantum dot (QD) radius, QD height, wetting layer (WL) thickness, and even potential barrier for coupled conical shape QD with WL system. For its reliable comparison, another two QDs proposed namely cylindrical and spherical QD, coupled with WL. These nanostructures are modeled with InAs and GaAs material. The InAs is considered to form QDs with WL on the GaAs substrate. We have computed the eigen energies corresponding to the carrier confined in three-dimensional QDs with a WL (quantum well) coupled system. The problems are formulated with effective mass approximation, Dirichlet and Neumann boundary conditions; and 1-band Schrodinger wave equation in partial differential equation are solved in coefficient form. The non-uniform finite element methodology discretized the Schrodinger wave equation. To find different state's eigenvalues the ARPCAK solver has been implemented. These methodologies are implemented on all proposed structures in this work for fair comparison. We observed that along with size confinement of QDs and WL, the potential barrier and different shapes also play crucial roles in modeling highly optimized QDs. From result analysis overall we found that the probability of finding e<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-</sup>is relatively large in CO-QD and eigen value are higher for SP-QD. The investigation revealed that the QDs have optimum radius for the given height and vice versa for the minimum bandgap and eventually the optimum optical efficiency. We also found that these optimized QDs have promising features that make them potentially usable in devices for quantum hardware in quantum computing for information processing.