Development of a high sensitivity photodetector using amorphous selenium and diamond cold cathode

Amorphous-selenium (a-Se) based photodetector is a promising candidate for high sensitivity imaging device with high spatial resolution, high response speed, and a wide detection wave range. Although HARP (high-gain avalanche rushing amorphous photoconductor) is known to be the first a-Se based photodetector that reported carrier multiplication and achieved effective quantum efficiency of 10, physical and chemical properties of the material are yet poorly understood. In this study, we carefully considered the recipe of a-Se and as a result, the necessary condition for obtaining the carrier multiplication has been clarified.