Magnesium incorporation during the molecular beam epitaxy growth of wurtzite GaN is found to invert the Ga-polar (0001) face to the N-polar face. The polarity is identified based on the two different sets of reconstructions seen on the film prior to and after about 1 monolayer Mg exposure. The inversion boundary is seen to lie on the (0001) plane from transmission electron microscopy images, an...

1 Introduction GaN-based wide-band gap materials continue to attract significant attention as promising candidates for the next generation of microwave communication systems and optoelectronic devices [1–3]. For all envisioned applications of GaN materials, it is important to effectively remove the generated heat. Thus, the thermal conductivity K value of GaN is a very important characteristic....

We report a comprehensive theoretical study of structural and electronic properties of substitutional oxygen and zinc contaminations in a model of single wall GaN nanotubes by means of ab initio supercell calculations. Our investigation yields many interesting results. The following ones deserve to be developed. Oxygen forms a shallow donor in the single wall GaN nanotubes as in bulk GaN polyty...

N-face AlGaN (cap)/GaN (channel)/AlGaN (barrier)/GaN (buffer) high electron mobility transistors (HEMTs) provide a simple solution for strong confinement of the two-dimensional electron gas (2DEG) from the back since carriers are induced on top of the AlGaN barrier. To reduce the adverse effects of random alloy scattering from the AlGaN barrier, an N-face GaN-spacer HEMT was designed with an ep...

As a result of their large band gap (~3.4 eV) and high breakdown electric field (>3x106 V/cm), GaN-based devices can operate at voltages higher than 100 V. Also, due to the strong piezoelectric effect and spontaneous polarization of both GaN and AlN, a high sheet carrier density (~1013 cm-2) can be achieved at the AlGaN/GaN heterointerface without any doping. In addition, high electron mobility...

Epitaxial GaN films were grown by metal organic chemical vapor deposition (MOCVD) on functionalized epitaxial graphene (EG) using a thin ( 11 nm) conformal AlN nucleation layer. Raman measurements show a graphene 2D peak at 2719 cm 1 after GaN growth. X-ray diffraction analysis reveals [0001]-oriented hexagonal GaN with (0002) peak rocking curve full width at the half maximum (FWHM) of 544 arcs...

Articles you may be interested in Exciton recombination dynamics in a-plane (Al,Ga)N/GaN quantum wells probed by picosecond photo and cathodoluminescence J. Low-temperature time-resolved cathodoluminescence study of exciton dynamics involving basal stacking faults in a-plane GaN Appl. Time-resolved cathodoluminescence and photocurrent study of the yellow band in Si-doped GaN Carrier relaxation ...

The e ects of impurity atoms as well as various growth methods to the formation of vacancy type defects in gallium nitride (GaN) have been studied by positron annihilation spectroscopy. It is shown that vacancy defects are formed in Ga or N sublattices depending on the doping of the material. Vacancies are decorated with impurity atoms leading to the compensation of the free carriers of the sam...

The optoelectronic properties of gallium nitride (GaN) have been well studied for decades, with results being translated to applications in solid state lighting and lasers, thermoelectricity, solar cells, power electronics, etc. However, the mechanical and tribological properties of GaN have been studied and understood far less than its optoelectronic properties. Our research aims to explore th...

We have studied the effects of rapid thermal annealing at 1300 °C on GaN epilayers grown on AlN buffered Si 111 and on sapphire substrates. After annealing, the epilayers grown on Si display visible alterations with craterlike morphology scattered over the surface. The annealed GaN/Si layers were characterized by a range of experimental techniques: scanning electron microscopy, optical confocal...