Recent development of high Al-content Al_xGa_1-xN made possible the fabrication of high speed UV photodetectors with high responsivity, low dark current. These UV photodetectors can be used in applications including flame and heat sensing, missile plume detection, environmental monitoring and several other commercial and DOD systems. The AlGaN bandgap can be tailored from 3.4 eV to 6.2 eV, corresponding to a band-edge wavelength range of 365nm to 200nm.

This work involved the characterization of ultraviolet p-i-n photodetectors based on AlGaN. These ultraviolet detectors showed low leakage current and improved responsivities. Improvements in the device geometrical design and epitaxial structure resulted in high photo current gain.