GaN is grown by plasma assisted molecular beam epitaxy on ZnO(1 1 00) substrates. Well-oriented (1 1 00) GaN surfaces are obtained, and (1 1 01) oriented facets are also observed. On the GaN(1 1 00) surfaces under Ga-rich conditions a surface reconstruction with approximate symmetry of "4×5" is found. A model is proposed in which this reconstruction consists of 2 ≥ monolayers of Ga terminating ...

In this article two methods for improvements of (112̄2) oriented semipolar GaN grown by MOVPE on pre-structured sapphire substrates are investigated. The integration of a SiNx interlayer helps to obtain a better crystal quality. Also the overgrowth of the MOVPE samples by HVPE is a way to obtain a smoother GaN surface. A high incorporation of oxygen on (112̄2) oriented GaN compared to (0001) orie...

The GaN material parameters relevant to the negative di€erential resistance (NDR) devices are discussed, and their physical models based on the theoretical predictions and experimental device characteristics are introduced. Gunn diode design criteria were applied to design the GaN NDR diodes. A higher electrical strength of the GaN allowed operation with higher doping ( 10 cmÿ3) and at a higher...

(GaN)1-x(ZnO)x solid solution has attracted extensive attention due to its feasible band-gap tunability and excellent photocatalytic performance in overall water splitting. However, its potential application in the photodegradation of organic pollutants and environmental processing has rarely been reported. In this study, we developed a rapid synthesis process to fabricate porous (GaN)1-x(ZnO)x...

We have investigated the growth conditions of cubic GaN (β-GaN) layers on very thin SiC-covered Si(001) by using gas-source molecular beam epitaxy as functions of SiC layer thickness, Ga-cell temperature and substrate temperature. Under the present SiC formation conditions on Si substrates by carbonization using C2H2 gas, the SiC layers with the thickness between 2.5 and 4 nm result in the epit...

We report direct self-heating measurements for AlGaN/GaN heterostructure field effect transistor grown on SiC. Measurements are carried out using micro-Raman scattering excited by above band gap ultraviolet and below band gap visible laser light. Ultraviolet excitation probes the GaN near the AlGaN/GaN interface region of the device where the two-dimensional electron gas carries the source-drai...

The Schottky barrier heights of metal contacts, including WSi0.8, Cr, Ti, Pt, and Ni, on n-type gallium nitride GaN with a GaN cap layer grown at low-temperature LTG were studied. Higher barriers can be formed by introducing LTG GaN on top of the conventional structures. The higher Schottky barrier observed in samples with the LTG GaN cap layer may be due to the facts that the high-resistivity ...

We report accurate energetics of defects introduced in GaN on doping with divalent metals, focusing on the technologically important case of Mg doping, using a model that takes into consideration both the effect of hole localization and dipolar polarization of the host material, and includes a well-defined reference level. Defect formation and ionization energies show that divalent dopants are ...

Introduction Recent history has seen the market for Gallium Nitride (GaN) devices grow dramatically with the LED chip market alone predicted to reach $3.4 billion by the end of 2003. Combine this with the emergence of next generation DVD players, which use the GaN blue laser technology, unique GaN high power/high frequency devices and GaN photodetectors and the importance of GaN technology can ...

This work presents measured results demonstrating an uncooled infrared (IR) detector based on gallium nitride (GaN) micromechanical resonators. GaN-based photonic detectors are typically designed to operate in the ultraviolet (UV) regime as the absorption spectrum of wide-band gap GaN peaks at a wavelength of ~360 nm. In contrast, the transduction mechanism of the device presented in this work ...