Comparison of deep level spectra in p-type and n-type GaN grown by molecular beam epitaxy

摘要

Deep levels in n-type GaN: Si and p-type GaN: Mg grown by molecular beam epitaxy were compared using deep level optical spectrscopy (DLOS). For n-GaN, the major bandgap states were observed to lie within 1 eV of the valence band edge. For the p-type film, hole photoemission from deep levels at near the conduction band edge and electron photoemission from a deep level near the valence band edge were resolved. Overall, the p-GaN filmed incorporated nearly ten times greater deep level concentration. Bandgap states attributed to residual carbon impurities with large concentration were found near the minority band edge in both films. (c) 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.