STRONG PHOTOLUMINESCENCE EMISSION FROM GAN GROWN ON AMORPHOUS SILICA SUBSTRATES BY GAS-SOURCE MBE

GaN layers are grown on amorphous fused silica glass substrates by gas source MBE using an ion removed electron cyclotron resonance (ECR) ra dical cell. Reflection high-energy electron diffraction (RHEED) and X- ray diffraction measurements reveal that they are polycrystalline. How ever, they show a strong photoluminescence emission peak without deep level emission. The emission peak is red-shifted by about 150 meV from that of the excitonic emission peak of GaN grown on a sapphire substr ate and has wide spectral half-width (similar to 250 meV at 77 K). The peak is not corresponding to the donor-acceptor pair (DAP) emission b ut is excitonic from the excitation power and temperature dependence o f PL spectrum. These optical properties indicate that GaN layers grown on a glass substrate are promising for fabrication of large area and low cost light emitting devices and solar cells. (C) 1998 Elsevier Sci ence B.V. All rights reserved.