Energy Focus: Gallium nitride goes vertical

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...

First-principles total-energy calculation of gallium nitride.

Gallium nitride (GaN) is a tetrahedrally coordinated III-V compound semiconductor which has the hexagonal wurtzite structure with a wide band gap of 3.5 eV at 300 K. It is reported that a simple-metal-insulator-n-typeGaN diode produces blue electroluminescence. ' For this reason it has been studied as a material suitable for an effective optoelectronic device such as laser and light emitting di...

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