This SBIR phase I project will substantially improve III-Nitride photovoltaic detector quantum efficiency by real-time control of fundamental material properties. Specifically, minority carrier diffusion length in (Al)GaN photodetectors will be manipulated to achieve up to 10-fold increase in photodetector efficiency in the range 20-300 nm. The innovation builds on recent discovery of increased minority-carrier diffusion length and lifetime following brief forward-bias electron injection into p-(Al)GaN in p-n junctions or Schottky barriers. Consistent long-term improvements were observed in the optoelectronic properties, including spectral and temporal photoresponse. Increased diffusion length improves minority-carrier collection and eliminates "dead space", where carriers recombine before collection. The practical significance of the innovation is a lasting (days), remarkable (10-fold) quantum-efficiency enhancement for (Al)GaN-based photovoltaic detectors achieved through short time (seconds) electron injection. POTENTIAL COMMERCIAL APPLICATIONS UV photo-detector applications that may be impacted by the proposed innovation, include UV Curing and Drying Control, Arc Detection, Phototherapy Control, Spectroscopy, Combustion Monitoring, Solar Irradiance Measurement, Sterilization and Purification Control, Medical Engineering, Dermatology, Output check of UV-lamps and gas burner flames, Measurement and control of ecological parameters, Control of solar radiation, UV water purification facilities, Deep-UV laser-induced fluorescence detector for naturally fluorescent molecules, UV-based transceiver for covert non-line-of-sight communicaitons.
