High-voltage photoconductive semiconductor switches fabricated on semi-insulating HVPE GaN: Fe template

In this work, high-voltage photoconductive semiconductor switches (PCSSs) with inter-digitated contact electrodes are directly fabricated on semi-insultating HVPE GaN:Fe template. The PCSS exhibits a cutoff wavelength of 365 nm and a dark resistivity of ∼10¹⁰ Ω cm. A maximum blocking voltage of more than 1100 V is obtained, corresponding to a breakdown electric field higher than 1.57 MV/cm for the GaN:Fe template. When excited by a 266 nm ultraviolet pulsed laser, the PCSS under 550 V bias could produce a peak photocurrent density of 387 A/cm² within a rise time of ∼20 ns. The fall time of the photocurrent pulse is mainly RC time limited.