A study on electronic properties of semiconductor nanostructures for applications as electronic and optoelectronic devices

Abstract

We have investigated fundamental physics of the developed numerical simulation programs to calculate electronic properties in nanostructures. And we have compared with several experiments and simulation results obtained from the developed simulators. The interband transitions in the self-assembled CdTe and Cd_(x)Zn_(1-x)Te quantum wires (QWRs) grown by using molecular beam epitaxy (MBE) and atomic layer epitaxy (ALE) were investigated by using temperature-dependent photoluminescence (PL) measurements. The shape of the CdTe and Cd_(x)Zn_(1-x)Te QWRs on the basis of the atomic force microscopy image was modeled to be a half-ellipsoidal cylinder approximately. Strain distributions, carrier distributions, and electronic subband energies were numerically calculated by using a finite difference method (FDM) with and without taking into account shape-based strain effects and nonparabolicity effect. Especially the electronic subband energies at several temperatures were numerically calculated by using a FDM with and without taking into account shape-based strain effects. The excitonic peak corresponding to (E1-HH1) interband transitions for nanostructure, as determined from the temperature- and structure- dependent PL spectra, were in reasonable agreement with the theoretical (E1- HH1) transitions calculated by using a FDM taking into account shape-based strain effects. These results can help improve understanding of the electronic structures, such as the strain distributions, the carrier distributions, and the electronic subband energies, in 2-D nanostructure. And these results provide a basic data to describe scattering mechanism and tunneling rates in nanostructure electronic transport.