Amorphous selenium photodetector driven by diamond cold cathode

Amorphous selenium is one of the most promising candidates as photoconducting material for future imaging devices. It can exhibit ultra-high photosensitivity by using avalanche multiplication inside the solid. However, the requirement of high vacuum by the electron emitters prevents amorphous selenium from being a realistic imaging device in general. Diamond, with its outstanding properties of negative electron affinity and high chemical stability, can be an ultimate emitter with low extraction field and low vacuum operation, especially for imaging devices. This report presents the first successful operation of an amorphous selenium photodetector with low operational vacuum and extraction field using a diamond cold cathode.