Yellow emission of GaN nanocrystals embedded in a silica xerogel matrix

Abstract

Abstract The synthesis, structural characterization, photoluminescence, and cathodoluminescence properties of nanocrystalline GaN, incorporated into silica sol–gel glass have been presented. Transmission electron microscopy techniques (TEM, HRTEM, and SAED) and X-ray diffraction (XRD) were used for characterization of the structure, phase composition, and morphology of the xerogel composite. Depending on the nitridation temperature the GaN semiconductor materials with average nanocrystallite sizes ranging from 4–5 nm up to about of 10 nm were prepared by the sol–gel technique. The origin of weak blue band luminescence localized at 355 nm is associated with the band gap of semiconductor at 3.4 eV. The dominating yellow luminescence band centered at 545 nm is due to the lattice defects.