Numerical Simulation of electronic properties in quantum dot heterostructures

A confined structure in all three dimensions leads to carrier's discrete energy level spectrum in quantum dots. This property has profound impact on many applications, such as single electron transistors, quantum dot laser, high efficiency photovoltaic cells, information storage etc. A finite element method is utilized to model the residual stress distribution. The effect of residual stress on the electronic and optical properties is studied. This is accomplished by incorporating both the valence subbands and the strain-induced potential field into Schr dinger equation. A finite-difference method was applied to solve the equation system. The density of states is obtained from the spectrum of the eigenstates. The discrete eigenstate distributions for both with and without residual stress are compared. The effect of the quantum dot size and geometry to the energy state distribution is discussed.