A study of the transport properties of polarizationinduced 2DEGs at MBE-grown single AlN/GaN heterostructures with different growth rates is reported. It is observed that faster growth rates lead to high mobilities, approaching ∼ 1600 cm2/Vs at 300 K and ∼ 6000 cm2/Vs at low temperatures for ultrathin ( 2.3 nm AlN/GaN) heterojunctions. By using a theoretical model in conjunction with experiment...

The effect of thickness of the high-temperature (HT) AlN buffer layer on the properties of GaN grown on Si(1 1 1) has been investigated. Optical microscopy (OM), atomic force microscopy (AFM) and X-ray diffraction (XRD) are employed to characterize these samples grown by metal-organic chemical vapor deposition (MOCVD). The results demonstrate that the morphology and crystalline properties of th...

We present our recent results on the growth of cubic AlN (001) layers by plasma assisted molecular beam epitaxy (PAMBE) using freestanding 3C-SiC (001) substrate. For high-quality c-AlN layers reflection high-electron energy diffraction (RHEED) patterns in all azimuths show RHEED patterns of the cubic lattice, hexagonal reflections are absent. Highresolution X-ray diffraction (HRXRD) measuremen...

In pursuit of lightweighting of automobiles and low emission of transportation, the efforts to develop high-strength, heat-resistant and fatigue-resistant Al alloys and/or composites have been ongoing. Here we report a novel Al matrix composite with ultrahigh strength reinforced by a three dimensional network of nano-AlN particles for the first time. The in-situ synthesized AlN particles are co...

Article history: Received 17 March 2016 Received in revised form 21 May 2016 Accepted 22 May 2016 Available online 7 June 2016 X-ray nano-diffraction and transmission electron microscopy were conducted along the thickness of a ~4 μm thick CrN/AlN multilayer with continuously increasing AlN layer thicknesses from ~1 to 15 nm on ~7 nm thick CrN template layers. The experiments reveal coherent gro...

Piezoelectric micromachined circular diaphragm energy harvesters for pulsed pressure sources have been fabricated and characterized. These devices utilize silicon carbide (SiC) as the structural material and aluminum nitride (AlN) as the active piezoelectric element to enable operation within harsh environments. In particular, the SiC/AlN energy harvesting device yields an output power density ...

This study investigated the effects of alendronate (ALN) on critical cell factors in osteoclasts. RAW 264.7 cells were induced by sRANKL to change to mature osteoclasts. On the sixth day of incubation, the osteoclasts were treated with ALN at various concentrations and for different incubation times. The concentration groups included 10-5 M, 10-6 M and 10-7 M ALN, respectively. The cells were i...

Recently, AlN plasma-enhanced atomic layer deposition (ALD) passivation technique had been proposed and investigated for suppressing the dynamic on-resistance degradation behavior of high-electron-mobility transistors (HEMTs). In this paper, a novel gate dielectric and passivation technique for GaN-on-Si AlGaN/GaN metal-insulator-semiconductor high-electron-mobility transistors (MISHEMTs) is pr...

We report on the numerical analysis of the electrical and optical properties of current-injected III-nitride based vertical-cavity surface-emitting lasers (VCSELs) with three types of current confinement schemes: the conventional planar-indium tin oxide (ITO) type, the AlN-buried type without ITO, and the hybrid type. The proposed hybrid structure, which combines an ITO layer and an intracavity...

A multi-faceted study on the reduction of ohmic contact resistance to AlN/GaN-based heterostructures is presented. Minimum contact resistance of 0.5 X mm has been achieved by partially etching the AlN barrier layer using a chlorine-based plasma dry-etch prior to ohmic contact metallization. For thin GaNcapped AlN/GaN heterostructures, we find it is necessary to remove the GaN cap in the vicinit...