Photoluminescence and optical absorption edge for MOVPE‐grown InN

Abstract

AbstractThis paper reports the photoluminescence (PL) spectra and the optical absorption edge at room temperature for MOVPE grown InN films as a function of growth temperature and background carrier concentration. A strong PL band with a peak energy in the range 0.7–0.9 eV is observed at room temperature. A sample grown at around 600 °C shows the highest PL intensity and the lowest peak energy. With decreasing the growth temperature from 600 °C, the PL intensity is markedly decreased and the peak energy is shifted toward the higher energy side. The absorption edge shows a similar change with the PL peak energy when the growth temperature is decreased. The difference between absorption edge and the PL peak energy is 50–100 meVand it increases with increasing the carrier concentration. The changes in PL peak energy and absorption edge with carrier concentration are not so steep compared to the absorption edge change predicted by Davydov et al. This may be explained by the increase in electron effective mass with increasing the carrier concentration reported by Wu et al. [Phys. Rev. B 66, 201403 (2002)]. (© 2003 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)