Recent developments of wide-bandgap semiconductor based UV sensors

Future missions for space astronomy and solar research require innovative vacuum ultraviolet (VUV) photodetectors. Present UV and VUV detectors exhibit serious limitations in performance, technology complexity and lifetime stability. New developments of metal-semiconductor-metal (MSM) solar-blind photodetectors based on diamond, cubic boron nitride (c-BN), and wurtzite aluminum nitride (AlN) are reported. In the wavelength range of interest. the characteristics of the MSM photodetectors present extremely low dark current. high breakdown voltage. and good responsivity. Diamond, c-BN, and AlN MSM photodetectors are sensitive and stable under UV irradiation. They show a 200 nm to 400 nm rejection ratio of more than four orders of magnitude and demonstrate the advantages of wide band gap materials for VUV radiation detection in space. (C) 2008 Elsevier B.V. All rights reserved.