Electronic structure of In_1-xGa_xAs quantum dots via finite difference time domain method

We have modified the filter diagonalization method and introduced a continuous gatelike filtering function in the propagation of a random-noise function via the finite difference time domain method to calculate the eigenstates of quantum dot structures. The propagation has been done by the split-operation method in analytically stretched coordinates in complex time domain to ensure the stability. We have demonstrated that the new algorithm is easy to implement, and it greatly improves the efficiency of the simulation making it a useful tool for the electronic calculation in complex systems. We have employed the modified method to calculate the confined states of the electrons and holes in InGaAs/InGaAsP quantum dot structure on a lattice matched (100) InP substrate. The photoluminescence (PL) spectra calculated from the eigenstates of the confined states agree well with reported experiment data.