Elasto-plastic mechanical deformation behaviors of c-plane (0001) and nonpolar GaN single crystals are studied using nanoindentation, cathodoluminescence, and transmission electron microscopy. Nanoindentation tests show that c-plane GaN is less susceptible to plastic deformation and has higher hardness and Young's modulus than the nonpolar GaN. Cathodoluminescence and transmission electron micr...

Single-crystal n-type GaN nanowires have been grown epitaxially on a Mg-doped p-type GaN substrate. Piezoelectric nanognerators based on GaN nanowires are investigated by conductive AFM, and the results showed an output power density of nearly 12.5 mW/m(2). Luminous LED modules based on n-GaN nanowires/p-GaN substrate have been fabricated. CCD images of the lighted LED and the corresponding ele...

A sample of the β-Ga2O3/wurtzite GaN heterostructure has been grown by dry thermal oxidation of GaN on a sapphire substrate. X-ray diffraction measurements show that the β-Ga2O3 layer was formed epitaxially on GaN. The valence band offset of the β-Ga2O3/wurtzite GaN heterostructure is measured by X-ray photoelectron spectroscopy. It is demonstrated that the valence band of the β-Ga2O3/GaN struc...

Crystalline GaN films can be grown even on amorphous substrates with the use of graphene buffer layers by pulsed sputtering deposition (PSD). The graphene buffer layers allowed us to grow highly c-axisoriented GaN films at low substrate temperatures. Full-color GaN-based LEDs can be fabricated on the GaN/graphene structures and they are operated successfully. This indicates that the present tec...

High-power operation of AlGaN/GaN highelectron-mobility transistors (HEMTs) requires efficient heat removal through the substrate. GaN composite substrates including high-thermal-conductivity substrates such as SiC and diamond are promising, but these composite substrates require careful attention to thermal resistances at GaN-substrate interfaces. We report on thermal characterization of GaN-o...

This work presents a new type of polarization-free GaN emitter. The unique aspect of this work is that the ultraviolet and visible emission originates from the cubic phase GaN and the cubic phase InGaN/GaN multi-quantum-wells, respectively. Conventionally, GaN emitters (e.g. light emitting diodes, laser diodes) are wurtzite phase thus strong polarization fields exist across the structure contri...

Nanotechnology is a rapidly growing and promising field of interest in medicine; however, nanoparticle-cell interactions are not yet fully understood. The goal of this work was to examine the interaction between endothelial cells and gallium nitride (GaN) semiconductor nanoparticles. Cellular viability, adhesion, proliferation, and uptake of nanoparticles by endothelial cells were investigated....

Gallium nitride [GaN] nanorods grown on a Si(111) substrate at 720°C via plasma-assisted molecular beam epitaxy were studied by field-emission electron microscopy and cathodoluminescence [CL]. The surface topography and optical properties of the GaN nanorod cluster and single GaN nanorod were measured and discussed. The defect-related CL spectra of GaN nanorods and their dependence on temperatu...

In present work, we have calculated the electronic properties including density of states and electron density for GaN, InN and InxGa1-xN  in wurtzite phase for x=0.5. The study is based on density functional theory with full potential linearized augmented plane wave method by generalized gradient approximation for calculating electronic properties. In this report we concluded that InxGa1-xN ba...

Giant axonal neuropathy (GAN) is caused by loss of function of the gigaxonin protein. On a cellular level GAN is characterized by intermediate filament (IF) aggregation, leading to a progressive and fatal peripheral neuropathy in humans. This study sought to determine if re-introduction of the GAN gene into GAN-deficient cells and mice would restore proper cytoskeleton IF homeostasis. Treatment...