GaN UV detectors for synchrotron-based protein structure studies

Blue, A. , Grant, J. , Cunningham, W. , Quarati, F., Smith, K.M., Rahman, M., O'Shea, V. and Manolopoulos, S. (2005) GaN UV detectors for synchrotron-based protein structure studies. Nuclear Instruments and Methods in Physics Research. Section A: Accelerators, Spectrometers, Detectors, and Associated Equipment, 546(1-2), pp. 131-134. (doi: 10.1016/j.nima.2005.03.115)

Abstract

AlGaN and GaN have been investigated as UVdetector materials for applications in proteinstructurestudies. I–V characteristics performed on the material using concentric contacts showed 4 orders of magnitude of greater dark current for the Al0.1Ga0.9N than for the GaN. Subsequently, interdigitated metal–semiconductor–metal (MSM) photodetectors were successfully fabricated on GaN. No changes in levels of dark surrent were recorded using varying metal electrodes with similar work functions (Pd and Au). The unbiased diodes showed a difference of 3 orders of magnitude between dark and photocurrent levels on exposure to UV. The responsivity for diodes with 25 and 100µm source finger separation operated in unbiased mode was around 100 mA/W and was flat over the bandgap. These results show a responsivity in agreement with those from previous measurements for biased GaN photodetectors [Phys. Stat. Solid: 176 (1999) 157]. Using these results, a design for an unbiased GaNdetector to be used for proteinstructurestudies is proposed.

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Blue, Dr Andrew and O'Shea, Professor Val and Grant, Dr James and Cunningham, Dr Liam and Smith, Professor Kenway
• Authors: Blue, A., Grant, J., Cunningham, W., Quarati, F., Smith, K.M., Rahman, M., O'Shea, V., and Manolopoulos, S.
• College/School: College of Science and Engineering > School of Physics and Astronomy
• Journal Name: Nuclear Instruments and Methods in Physics Research. Section A: Accelerators, Spectrometers, Detectors, and Associated Equipment
• ISSN: 0168-9002
• ISSN (Online): 1872-9576
• Published Online: 26 April 2005