Numerical Simulations of Residual Stresses and Their Effects on Electronic Properties in Quantum Dots
B. Vlahovic, V. Suslov and K. Wang
North Carolina Central University, US
Keywords: Quantum dots, residual stresses, electronic and optical properties
A finite element method has been utilized to simulate the residual stress distributions in the quantum dots. Both lattice mismatch and thermal expansion effects are included. Our calculation indicates that the residual stresses concentrate at the edge and the interface of the sample. The dominant effect which causes the residual stress is the lattice mismatch between quantum dot material and the substrate.
The effects of residual stresses on the electronic and optical properties are also studied. The additional potential field induced by the residual strain has been included in the time-independent Schrödinger equation to calculate the energies and wave functions.
The finite-difference method was applied to solve the confined state problem. The density of states can be obtained from the spectrum of the eigenstates in the numerical solutions. The effects of size, strain, composition and other parameters can be seen directly from the density of states. Comparison with available data, such as measurements of transport properties will be provided.
NSTI Nanotech 2003 Conference Technical Program Abstract