Morphologies and photoluminescence properties of GaN‐based thin films grown on non‐single‐crystalline substrates

Morphologies and photoluminescence properties of gallium nitride-based thin films grown on non-single-crystalline substrates were investigated. The films were directly grown on quartz glass and amorphous-carbon-coated graphite substrates by a molecular beam epitaxy apparatus which has dual nitrogen plasma cells. Co-supplying of indium and gallium with simultaneous operation of the dual nitrogen plasma cells brought isolated and nano-pillar-shaped structures to the films. On the other hand, such structures were not obtained when the films were grown by the single plasma cell operation. Photoluminescence (PL) properties of the films greatly depended upon the morphologies. The intensities of the PL peaks emitted from the films which have such nano-pillar shaped structures were quite intense although the peak energies shifted to lower energy sides compared with those of the films grown by the single plasma cell operation. (© 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)