Splitting of valance subbands in the wurtzite c-plane InGaN/GaN quantum well structure

Peak splitting in the low temperature photoluminescence (PL) spectra of c-plane InGaN/GaN single quantum well samples was observed. For the k parallel to c configuration, the splitting peaks show a variation in relative intensity as the excitation power is tuned. For the k perpendicular to c configuration, a strong polarization dependence of the luminescence distribution and intensity was spotted. The PL spectra was analyzed with a calculation model based on the k.p effective mass theory, and the splitting peaks were identified as free-exciton transitions between the conduction subband C-1 and two groups of valence subbands, the {HH1,LH1} and the {HH2,LH2,CH1}, respectively. (C) 2008 American Institute of Physics. [DOI: 10.1063/1.3007985]