Temperature dependence of the EL spectral intensity is investigated between 20 and 300 K of a particularly designed blue (In,Ga)N/GaN multiple-quantum-well (MQW) light-emitting-diode (LED), which contains an additionally n-doped (In,Ga)N electron reservoir layer. The MQW-LED consists of In0.3Ga0.7N MQW layers with a nominal well width of 2.5 nm separated by 6.5 nm GaN barrier layers, prepared b...

Low-temperature photoluminescence (PL) and optically detected magnetic resonance (ODMR) at 24GHz have been performed on a series of MBE-grown Mg-doped (10–10 cm ) GaN homoepitaxial layers. High-resolution PL at 5K revealed intense bandedge emission with narrow linewidths (0.2–0.4meV) attributed to annihilation of excitons bound to shallow Mg acceptors. In contrast to many previous reports for G...

Magnetic resonance experiments, including optically detected magnetic resonance (ODMR) and electron paramagnetic resonance (EPR), have been performed on Si-doped homoepitaxial GaN layers grown by MOCVD and on high quality, free-standing (B200mm-thick) GaN grown by HVPE. This allowed us to obtain information on the properties of native defects and dopants in GaN with a significantly reduced dens...

Low Al-composition p-GaN/Mg-doped Al0.25Ga0.75N/n(+)-GaN polarization-induced backward tunneling junction (PIBTJ) was grown by metal-organic chemical vapor deposition on sapphire substrate. A self-consistent solution of Poisson-Schrödinger equations combined with polarization-induced theory was used to model PIBTJ structure, energy band diagrams and free carrier concentrations distribution. The...

A general approach for the synthesis of manganese-doped II-VI and III-V nanowires based on metal nanocluster-catalyzed chemical vapor deposition has been developed. High-resolution transmission electron microscopy and energy-dispersive X-ray spectroscopy studies of Mn-doped CdS, ZnS, and GaN nanowires demonstrate that the nanowires are single-crystal structures and homogeneously doped with cont...

We apply positron annihilation spectroscopy to identify V(N)-Mg(Ga) complexes as native defects in Mg-doped GaN. These defects dissociate in postgrowth annealings at 500-800 degrees C. We conclude that V(N)-Mg(Ga) complexes contribute to the electrical compensation of Mg as well as the activation of p-type conductivity in the annealing. The observation of V(N)-Mg(Ga) complexes confirms that vac...

GaN nanowall network was epitaxially grown on Si (111) substrate by molecular beam epitaxy. GaN nanowalls overlap and interlace with one another, together with large numbers of holes, forming a continuous porous GaN nanowall network. The width of the GaN nanowall can be controlled, ranging from 30 to 200 nm by adjusting the N/Ga ratio. Characterization results of a transmission electron microsc...

We report on the photoluminescence properties of erbium Er doped InxGa1−xNa epilayers synthesized by metal organic chemical vapor deposition. The crystalline quality and surface morphology of Er doped In0.05Ga0.95N were nearly identical to those of Er doped GaN. The photoluminescence intensity of the 1.54 m emission in Er doped In0.05Ga0.95N was an order of magnitude lower than in Er doped GaN ...

A classification in terms of the localization of donor defects in GaN is performed by Raman spectroscopy under large hydrostatic pressure. We observe a significant decrease of the free carrier concentration in highly O doped GaN epitaxial films at a hydrostatic pressure of 22 GPa. This indicates the presence of a strongly localized donor defect at large pressure. Monitoring the phonon plasmon c...

Magnesium-doped gallium nitride nanowires have been synthesized via metal-catalyzed chemical vapor deposition. Nanowires prepared on c-plane sapphire substrates were found to grow normal to the substrate, and transmission electron microscopy studies demonstrated that the nanowires had single-crystal structures with a 〈0001〉 growth axis that is consistent with substrate epitaxy. Individual magne...