GaN UV detectors for protein studies

GaN and its ternary alloy AlGaN have been investigated as UV detector materials for applications in protein structure studies. Interdigitated metal–semiconductor–metal (MSM) finger photodiodes, with finger spacings/widths of 5 and 10 μ m , were successfully fabricated on six different GaN/AlGaN materials. Current–Voltage (I–V) characteristics and spectral response measurements were made on completed devices. The results showed negligible difference in performance between the 5 μ m finger spacing/width diode design and the 10 μ m finger spacing/width diode design. Using these results, a 46 channel diode array, with a finger spacing/width of 10 μ m , was successfully fabricated on 2.5 μ m thick epitaxial GaN. This 46 channel diode array will be used in a protein structure experiment at the Daresbury SRS.