UV Optoelectronic Devices Based on Nonpolar and Semi-polar AlInN and AlInGaN Alloys

Brief Description

A device structure that can be used to create high-power and high-efficiency LEDs and LDs in the UV range of the spectrum. 

Background

Nitride-based optoelectronics have been studied extensively in order to fabricate visible and UV light-emitting devices. While high-power and high-efficiency LEDs and LDs that emit in the visible spectrum have been achieved, devices that emit in the deep UV region of the spectrum (less than roughly 360 nm) with similar desirable qualities have not due to growth difficulties resulting in poor material quality.

Description

Researchers at UC Santa Barbara have developed a device structure that can be used to create high-power and high-efficiency LEDs and LDs in the UV range of the spectrum. The devices emit in the wavelength range from 280 nm to 360 nm using a nonpolar or semi-polar AlInN and AlInGaN layer grown on a nonpolar or semi-polar bulk GaN substrate. In this device configuration, the piezoelectric field is reduced as the AlInN and AlInGaN layers are lattice-matched to GaN. Polarization is minimized by growing along nonpolar or semi-polar orientations, thus creating a relatively wide bandgap and minimizing the reduction of the radiative recombination efficiency and the effects of the quantum-confined Stark effect. 

Advantages

·         Higher efficiency UV light emitting devices

·         Reduced spontaneous polarization effects

·         Reduction in the quantum confined Stark effect (QCSE)

Applications

·         UV LEDs and LDs

·         Water- and air-purification systems

·         Germicidal and biomedical instrumentation systems

Patent Status