Fabrication of a layered gallium selenide photodetector array via oxygen plasma etching

Abstract

We investigated a processing method for gallium selenide photodetectors to increase manufacturing throughput and achieve element integration. Films can be processed using oxygen plasma irradiation without compromising the device performance. The responsivity was increased with the film thickness and became more pronounced with decreasing crystal size. The detectivity changed within an error margin of less than two orders of magnitude of the obtained value. The sensitivity, which was defined as the photo-to-dark current ratio, increased when the film was thicker and larger. Photodetector array comprising of 3 × 3 pixels was fabricated, and all the element devices exhibited similar performances.