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Ga(S2CN(CH3)2)3(Ga(mDTC)3) nanoparticles (NPs) were prepared using ultrasonic spray method, and well mono-dispersed, with a mean particles size of 82 nm. Ga(mDTC)3NPs changed into Ga2S3at 300°C under N2environment, and the spin-coated films transformed into GaN films above 700°C under NH3environment. From these results, Ga(mDTC)3films were transformed into γ-Ga2S3films by thermal decomposition, and S elements were substituted simultaneously by N elements. In this stage, the pyrolytic GaN film underwent a recrystallization process, and a preferred direction of GaN films was mainly aligned to z-axis direction due to the lower energy surface of hexagonal structure. [ABSTRACT FROM AUTHOR]

Growth conditions have a tremendous impact on the unintentional background impurity concentration in gallium nitride (GaN) synthesized by molecular beam epitaxy and its resulting chemical and physical properties. In particular for oxygen identified as the dominant background impurity we demonstrate that under optimized growth stoichiometry the growth temperature is the key parameter to control its incorporation and that an increase by 55 °C leads to an oxygen reduction by one order of magnitude. Quantitatively this reduction and the resulting optical and electrical properties are analyzed by secondary ion mass spectroscopy, photoluminescence, capacitance versus voltage measurements, low temperature magneto-transport and parasitic current paths in lateral transistor test structures based on two-dimensional electron gases. At a growth temperature of 665 °C the residual charge carrier concentration is decreased to below 1015 cm−3, resulting in insulating behavior and thus making the material suitable for beyond state-of-the-art device applications. [ABSTRACT FROM PUBLISHER]

The possibility that GaN charged nanoparticles might be generated during the synthesis of GaN nanostructures was examined in an atmospheric-pressure chemical vapor deposition (CVD) process using a differential mobility analyzer combined with a Faraday cup electrometer. Both positively and negatively charged nanoparticles in the size range of 10–100 nm were generated in the reactor of the CVD process using Ga2O3 precursor and NH3 gas. With decreasing flow rate of NH3 from 400 to 0 standard cubic centimeter per min (sccm) and decreasing reactor temperature from 1100°C to 500°C, the size and the number concentration of charged nanoparticles decreased. As the size and the number density decreased, the size of deposited GaN hexagonal crystals decreased and eventually GaN nanowires began to grow without catalysts. Copyright 2012 American Association for Aerosol Research [ABSTRACT FROM AUTHOR]