Formation of p‐n Junction in a‐Se Thin Film and Its Application to High Sensitivity Photodetector Driven by Diamond Cold Cathode. Issue 11 (15th August 2017)

• Record Type: Journal Article
• Authors: Masuzawa, Tomoaki; Ohata, Akinori; John, Joshua D.; Saito, Ichitaro; Yamada, Takatoshi; Chua, Daniel H. C.; Neo, Yoichiro; Mimura, Hidenori; Okano, Ken
• Is Part Of: Physica status solidi. Volume 214:Issue 11(2017)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2017-08-15
• Subjects: amorphous materials -- carrier multiplication -- cold cathodes -- diamonds -- photodetectors -- selenium; Solid state physics -- Periodicals; Solids -- Industrial applications -- Periodicals; 530.41
• DOI: 10.1002/pssa.201700161
• Languages: English
• ISSNs: 1862-6300

Abstract

Abstract : In this study, photoconductor made of amorphous selenium (a‐Se) is studied to improve a sensitivity of vacuum‐tube type photodetectors. An electrochemical process was applied to a‐Se films to form a p‐n structure within the film. The formation of p‐n structure was confirmed by time‐of‐flight secondary ion mass spectroscopy as well as its electronic property. The a‐Se film was then combined into a prototype photodetector, and enhancement of sensitivity was evaluated in terms of nominal quantum efficiency and signal‐to‐noise ratio. The results showed that the formation of a p‐n junction within a‐Se film increased the sensitivity of the photodetector, especially at relatively low operation voltages. Abstract : This paper reports on sensitivity enhancement of a vacuum‐tube type photodetector using amorphous‐selenium (a‐Se) based photoconductor. Formation of a p‐n structure using a simple electrochemical process is described, of which enhances internal electric field in the a‐Se film and increases the sensitivity of the photodetector. The authors believe that this technique provides a new approach of sensor fabrication using amorphous semiconductors.