Optical Properties and Electronic Subband Structures in InxGa1-xN/GaN Single Quantum Wells

Abstract

An InxGa1-xN/GaN single quantum well (SQW) was grown and was investigated by X-ray diffraction (MID), photoluminescence (PL), and Hall measurements. The In composition of the InxGa1-xN layer was determined to be 30% from the XRD data. The activation energy of the excitons confined in the In0.3Ga0.7N/GaN SQWs: as obtained from the temperature-dependent PL spectra, was 70 meV. The electron and the hole states were calculated by using a multi-band (k) over right arrow . (p) over right arrow theory and considering the strain due to the lattice mismatch and the spontaneous and piezoelectric polarizations, and the results were compared with the PL data. The potential due to free carriers observed in the Hall measurement was also taken into account by solving the Schrodinger equation and the Poisson equation self-consistently. The calculated electronic structure of the In0.3Ga0.7N/GaN SQW showed that only one subband below the Fermi level was occupied by the elections. The present results help improve understanding of the electronic structures in InxGa1-x/GaN SQWs.