Semi-insulating GaN and its evaluation for α particle detection

The application of semi-insulating GaN for detection of ionising particles, specifically α-particles, is presented. The electrical properties of GaN epitaxial layers have been investigated and the space charge limited and Ohmic currents were observed. A microwave method was used for temporal measurements of the photocurrent. Transient behaviour of the injection current and photo-response was observed, with a wide range of instantaneous time constants. The charge collection efficiency was measured to be approximately 100% and the role of inhomogeneities in the charge collection peculiarities was analysed.