Native defects in gallium nitride

Nitrogen vacancies as major point defects in gallium nitride.

We present results of ab initio calculations for vacancies and divacancies in GaN. Particular attention is paid to nitrogen vacancies and mixed Ga-N divacancies in negatively charged states, which in n-type GaN are found to be energetically comparable with gallium vacancies. We also demonstrate that the activation energy for self-diffusion over the nitrogen sublattice is lower than over the gal...

Gallium Nitride Photoconductive Detectors

Since 1994, the Applied Physics Laboratory has been collaborating with NASA Goddard Space Flight Center to develop photodetectors based on gallium nitride and aluminum gallium nitride material produced in the Milton S. Eisenhower Research and Technology Development Center. This article describes the results of our collaboration and highlights the development of gallium nitride photodetectors wi...

Carrier Localization in Gallium Nitride

In wide bandgap GaN a large number of interesting and important scientific questions remain to be answered. For example, the large free electron concentration reaching 1019 to 1020 cm-3 in nominally undoped material are ascribed to intrinsic defects because no chemical impurity has been found at such high concentrations. According to theoretical models a nitrogen vacancy acts as a donor but its...

Single gallium nitride nanowire lasers.

There is much current interest in the optical properties of semiconductor nanowires, because the cylindrical geometry and strong two-dimensional confinement of electrons, holes and photons make them particularly attractive as potential building blocks for nanoscale electronics and optoelectronic devices, including lasersand nonlinear optical frequency converters. Gallium nitride (GaN) is a wide...

Gallium Nitride Nanowire Electromechanical Resonators