UV Wavelength Selective Quaternary GaN-based Sensors

WideGap Technology (WiTech) proposes to develop group-III nitride-based solar blind (<300 nm) photodetectors. The main goal of the proposed Phase I development is the fabrication of discrete, high-efficiency wavelength-selective (Al,Ga,In)N solid-state detectors using band gap engineering and advanced techniques of nitride materials growth. During Phase I we will develop two-flow atmospheric pressure MOCVD as a growth technique for the fabrication of nitride-based detector active layers and demonstrate prototypical photodiode structures which are sensitive to wavelengths shorter than 300 nm. The achievement of the Phase I project will facilitate the Phase II development of optimized detectors and full detector arrays which operate in the solar blind- UV spectrum without the need for external filters. Solid state photodetectors incorporate the benefits of reduced instrument complexity, mass and volume, and are capable of withstanding velocity shock incurred during launch. The robust nature of nitride semiconductors, which are capable of operating under extreme thermal conditions in harsh environments and are expected to exhibit superior radiation hardness characteristics compared to silicon, makes these materials well-suited to application in ground, air and spaceborne observational and guidance systems. Compact wavelength-selective detectors and arrays are attractive for a variety of military, industrial, and commercial applications such as missile detection and tracking, secure intersatellite communications, solar-blind W detectors, detection of biological and chemical agents, flame sensors, plasma diagnostics, engine monitoring and medical applications. The fabrication of wavelength-discriminating focal plane arrays would facilitate color-sensitive imaging.