In this work we have demonstrated nanoscale GaN device structures made from individual GaN nanowires and electrical contacts utilizing focused ion beam FIB induced Pt deposition. These GaN nanowires were grown by direct reaction of Ga vapor with NH3 and had diameters ranging from 100 nm to 250 nm and lengths up to 200 m. As-grown nanowires were dispersed on SiO2 coated p++ Si substrate. A 30 ke...

AlGaN/GaN HEMT is one of attractive candidates for next generation high power devices because of high carrier mobility in 2DEG channels and high breakdown voltage due high critical electric field. In order to apply the AlGaN/GaN HEMTs for power switching applications the normally off operation is required. Enhancement type behavior of GaN HEMT transistors is obtained by using p-type Mg-doped Ga...

GaN films have been grown at 1050 8C on porous silicon (PS) substrates by metalorganic vapour phase epitaxy. The annealing phase of PS has been studied in temperature range from 300 to 1000 8C during 10 min under a mixture of ammonia (NH3) and hydrogen (H2). The PS samples were characterized after annealing by scanning electronic microscope (SEM). We observed that the annealing under the GaN gr...

The PL of porous GaN sample shows higher intensity with smaller FWHM and red-shifting relative to the as-grown sample. The energy gap for porous GaN sample was smaller compare to the as-grown sample. The SEM surface image of UV-assisted electrochemical etching process is shown a shape and size of pore which was formed on the surface of the GaN, therefore the shape of pores formed was in spheric...

The synthesis of wurtzite gallium nitride (GaN) nanorods with triangular shape on c-Al2O3 substrates using a thermal chemical vapor deposition process was investigated. It was possible to control nanorod shape and growth mode of GaN nanorods by change of sample geometry in the chamber using a mixture of GaN powder and Ga metal with ammonia gas reaction. It was found that the GaN nanorods were g...

Vertical thin-GaN LED was successfully fabricated on the GaN LED epi-layers grown on the patternedsapphire substrate with the pyramidal pattern by low-temperature Cu/Sn/Ag wafer bonding at 150 C. An inverted pyramidal pattern formed on the n-GaN surface after the GaN epi-layer was transferred onto Si wafer, which resulted from the pyramidal pattern on the patterned-sapphire substrate. The inver...

Most III-nitride semiconductors are grown on non-lattice-matched substrates like sapphire or silicon due to the extreme difficulty of obtaining a native GaN substrate. We show that several layered transition-metal dichalcogenides are closely lattice-matched to GaN and report the growth of GaN on a range of such layered materials. We report detailed studies of the growth of GaN on mechanically-e...

Using first-principles theory, we predict ferromagnetism in Cr-doped GaN nanowires irrespective of the sites that the Cr atoms occupy. This is in contrast to Mn-doped GaN nanowires in which the magnetic coupling between the Mn atoms is sensitive to the Mn--Mn and Mn--N distances, although the ground state of Mn-doped GaN nanowires is ferromagnetic. Each Cr atom carries a magnetic moment of abou...

Structure shift of GaN nanowall network, nanocolumn, and compact film were successfully obtained on Si (111) by plasma-assisted molecular beam epitaxy (MBE). As is expected, growth of the GaN nanocolumns was observed in N-rich condition on bare Si, and the growth shifted to compact film when the Ga flux was improved. Interestingly, if an aluminum (Al) pre-deposition for 40 s was carried out pri...

Piezoelectrically actuated micromechanical resonators have been a subject of extensive research for the past decade with the main goal of replacing quartz resonators in timing applications. Aluminum nitride (AlN) has been the main contender as a piezoelectric ceramic replacement for quartz since its low-temperature sputtering process has been developed. In recent years, gallium nitride (GaN) ha...