OBSERVATION OF QUANTUM-CONFINED EXCITED-STATES OF GAN NANOCRYSTALS

GaN nanocrystals with an average diameter of 4.5 nm+/-1.6 nm were synt hesized by pulsed laser ablation of a gallium metal target in a nitrog en atmosphere. Transmission electron microscopy and selected area elec tron diffraction confirmed the hexagonal structure and size of the nan ocrystals. Optical absorption and photoluminescence spectroscopy revea led quantum confined excited states in the nanocrystalline samples wit h features at 4.43 eV (280 nm) and 5.47 eV (227 nm), (C) 1998 American Institute of Physics.