Multiphysics multiscale effects in two laterally coupled AlN/GaN quantum dots with wetting layer

摘要

Coupled Quantum Dots (QDs) or QDs arrays provide an attractive potential building block for the next generation logic devices in the existing post CMOS technology for the purpose of quantum computing. These QDs arrays also find applications in optoelectronic devices such as Vertical Cavity Surface Emitting Lasers (VCSEL), photo voltaic cells and others where they may face challenges from thermal loadings. The study of electromechanical effects in such devices becomes very important as most of the materials in semiconductor nano structures are piezoelectric in nature. At the same time, this study requires taking into account multiple scales at which such devices should be analyzed. In this paper, we present the numerical simulations for the band structure calculations of two laterally coupled truncated GaN/AlN QDs under the influence of thermoelectroelasticity. By using Finite Element Method (FEM), we study the effect of thermoelasticity on the electronic properties of the two laterally coupled truncated GaN/AlN QDs in the presence of wetting layers based on the 8 × 8 Hamiltonian. The numerical values of several parameters such as electromechanical fields, eigenvalues and electron wave functions in the two laterally coupled truncated GaN/AlN QDs have been reported and they are compared to the previously reported results for single GaN/AlN truncated QDs (Nanotechnology 20, 125402, 2009). Simulations results show that several identical electron wave functions are present in the same QDs. Due to electron wave functions overlap in laterally coupled QDs, these parameters become more sensitive to thermal loadings compared to single truncated quantum dots. Figure 1 and 2 are the illustration of the wave functions and eigenvalues of the ground and first excited states in the coupled QDs structure without thermopiezoelectric effects. This project has been funded by NSERC and CRC.