Paper Title
Study of Morphological, Structural, Optical and Transport Properties of Gallium Nitride Nanodots Fabricated Under Extreme Plasma Conditions

Abstract
In the present paper, we reported the fabrication of gallium nitride (GaN) nanostructures on sapphire substrates through the ions of GaN. These GaN ions are generated due to the interaction of GaN pellet with hot, dense and extremely non-equilibrium argon plasma in a modified dense plasma focus device. In the process of fabrication two bursts of focused plasma were used and the sapphire substrates were placed at distances of 4.0 cm and 5.0 cm from the top of central anode. Morphological studies using scanning electron microscopy reveals formation of nanodots having average diameter ~ 71 nm and ~ 35 nm at 4.0 cm and 5.0 cm distances, respectively. Formation of nanodots have been further confirmed in transmission electron microscopy results. X-ray diffraction pattern show peaks corresponding to hexagonal GaN. Photoluminescence spectra show emission peaks corresponding to band edge, blue and UV emissions. Optical absorption studies reveals increase in optical band gap of nanodots from that of bulk GaN. Transport studies using Hall measurement indicate n-type nature of fabricated GaN nanodots. The obtained optical and transport properties of GaN nanodots suggest the potential applications of nanodots in GaN based nano-optoelectronic devices. Keywords - Gallium Nitride, Dense Plasma Focus, Nanodots, Photoluminescence, Hall Measurement, Optoelectronic Devices.