Electronic Structures and Carrier Distributions of T-Shaped Al_xGa_(1-x)As/Al_yGa_(1-y)As Quantum Wires Fabricated by a Cleaved-Edge Overgrowth Method

摘要

The electronic structures and carrier distributions of T-shaped Al_xGa_(1-x)As/Al_yGa_(1-y)As quantum wire (QWR) consisting of crossed arm and stem wells were numerically calculated by using a finite-difference method (FDM). The electronic subband energies in the arm and the stem wells were numerically calculated by using the FDM taking into account two-band Hamiltonian systems considering with and without strain and nonparabolicity effects. The band deformation due to strain and the probabilistic electron confinement of T-shaped Al_xGa_(1-x)As/Al_yGa_(1-y)As QWRs were also calculated. The transition energy from the ground heavy-hole state (HH_1) to the ground electron state (E_1) was 1.584 eV when the strain was not considered and 1.585 eV when the strain effects were included. The excitonic peak energies corresponding to the interband transitions (E_1-HH_1) in the T-shaped QWRs determined from the photoluminescence spectra were compared favorably with those determined from the FDM calculations.