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 10μm, 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 5μm finger spacing/width diode design and the 10μm finger spacing/width diode design. Using these results, a 46 channel diode array, with a finger spacing/width of 10μm, was successfully fabricated on 2.5μm thick epitaxial GaN. This 46 channel diode array will be used in a protein structure experiment at the Daresbury SRS.