On optical polarization and charge carrier statistics of nonpolar InGaN quantum wells

Abstract

Abstractauthoren Optical polarization is a fundamental property of light emission from m-plane InGaN quantum wells. It is a result of band structure, anisotropic strain, the degree of polarization depending on thermal occupation, and band-filling of valence subbands. We analyze the optical-polarized light of nonpolar samples at low and at room temperature over a wide range of excitation density. We observe that the measured energy separation and linewidth of the orthogonally polarized emission depend on carrier density, too. A consistent explanation of these effects is possible in the context of Fermi–Dirac statistics for a degenerate carrier density and inhomogeneously broadened density of states. In addition, pulsed electroluminescence experiments were performed to validate our conclusions for optoelectronic devices based on nonpolar InGaN quantum wells.