Order of magnitude enhancement of AlGaN UV photo-detector efficiency

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.