The structural properties and the shape of self-assembled CdTe/ZnTe quantum wires ͑QWRs͒ grown by using molecular beam epitaxy and atomic layer epitaxy were determined by using atomic force microscopy ͑AFM͒ measurements, and the interband transitions in the CdTe/ZnTe QWRs were investigated by using temperature-dependent photoluminescence ͑PL͒ measurements. The shape of the CdTe/ZnTe QWRs on the basis of the AFM image was modeled to be a half-ellipsoidal cylinder approximately. The temperature-dependent PL spectra showed that the PL peaks corresponding to the interband transitions from the ground electronic subband to the ground heavy-hole band ͑E 1-HH 1 ͒ shifted to lower energy with increasing temperature. Strain distributions and electronic subband energies at several temperatures were numerically calculated by using a finite-difference method ͑FDM͒ with and without taking into account shape-based strain and nonparabolicity effects. The excitonic peak corresponding to ͑E 1-HH 1 ͒ interband transitions, as determined from the PL spectra, was in reasonable agreement with that corresponding to the ͑E 1-HH 1 ͒ transitions obtained, as determined from the FDM calculations taking into account shape-based strain and nonparabolicity effects. The present results help improve understanding of the electronic structures of CdTe/ZnTe QWRs.

Optical gains and interband transition energies for CdTe/ZnTe single quantum wells (SQWs) with different CdTe well widths were investigated. Photoluminescence (PL) spectra for CdTe/ZnTe SQWs at various temperatures were experimentally obtained, and the corresponding optical gains were calculated by using an interacting pair Green's function and by using an energy space integrated function. The peak energies in the gain spectra that take the Coulomb interaction between the electron and the hole into account were in qualitatively reasonable agreement with those determined from the PL spectra.

The optical and electronic properties in ͑In 0.53 Ga 0.47 As͒ 1−z / ͑In 0.52 Al 0.48 As͒ z digital alloys with various compositions grown on InP substrates by using molecular-beam epitaxy were investigated through photoluminescence ͑PL͒ measurements and numerical calculations. The electronic subband energy states, the interband transition energies, and the exciton binding energies of ͑In 0.53 Ga 0.47 As͒ 1−z / ͑In 0.52 Al 0.48 As͒ z digital alloys and corresponding In 0.53 Ga 0.47 As/ In 0.52 Al 0.48 As single quantum wells were calculated by using a finite difference method, taking into account two band Hamiltonian system. The numerical results for interband transitions of ͑In 0.53 Ga 0.47 As͒ 1−z / ͑In 0.52 Al 0.48 As͒ z digital alloys were in reasonable agreement with the excitonic transitions obtained from the PL measurements.

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Strain distributions and interband transitions of CdxZn1−xTe/ZnTe asymmetric double quantum dots (DQDs) with different degree of coupling were calculated by using a three-dimensional finite difference method (FDM) taking into account strain and nonparabolicity effects. Bird’s-eye views of the truncated contour plots of the ground state wave functions at the conduction band of the Cd0.6Zn0.4Te/ZnTe DQDs showed the transition behavior from the coupling to the decoupling behaviors with increasing ZnTe spacer layer thickness. The interband transition energies from the ground electronic subband to the ground heavy-hole band (E1-HH1) in the CdxZn1−xTe/ZnTe DQDs, as determined from the FDM calculations, were in reasonable agreement with the experimental peaks of the temperature-dependent photoluminescence spectra corresponding to the (E1-HH1) interband transition energies in the temperature range from 32 to 130 K.