Amorphous selenium photodetector driven by diamond cold cathode

Among large amounts of reports on imaging devices, amorphous selenium is one of the most promising, candidates as photoconducting material ford future imaging devices. Amorphous selenium can exhibit ultra-high photosensitivity by using avalanche multiplication inside the solid. However, requirement of high vacuum by electron emitters prevents amorphous selenium from being a realistic imaging device in general. Diamond, with its outstanding properties such as negative electron affinity and high chemical stability, can be an ultimate emitter with low extraction field and low vacuum operation, especially for the 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.