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Title: Thermal stability and photoconductive properties of photosensors with an alternating multilayer structure of amorphous Se and As{sub x}Se{sub 1−x}

In this study, we fabricated a-Se based photosensors with an alternating multilayer structure of a-Se and As{sub x}Se{sub 1−x} by rotational thermal evaporation deposition. During the deposition of the amorphous As{sub x}Se{sub 1−x} layers, As diffuses into the underlying a-Se component layers, thereby improving the thermal stability of the multilayer photosensor and thus increasing the breakdown electric field. Although the As doping introduces carrier traps in the a-Se layers, the multilayer photosensors demonstrate an effective quantum efficiency comparable to the single-layered a-Se sensor under the blue light illumination but are with a lower dark current density by two orders of magnitude. In addition to the top As{sub x}Se{sub 1−x} layer being functioning as an electron blocking layer, carrier traps present in the multilayer structure may decrease the drift mobility of charge carriers and disturb electric field distribution in the photosensors, thereby suppressing the dark current.
Authors:
; ; ; ;  [1]
  1. Department of Materials Science and Engineering, National Chiao-Tung University, Hsinchu 30010, Taiwan (China)
Publication Date:
OSTI Identifier:
22494658
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 118; Journal Issue: 4; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; ARSENIC SELENIDES; CARRIER MOBILITY; CARRIERS; CHARGE CARRIERS; CURRENT DENSITY; DEPLETION LAYER; DEPOSITION; ELECTRIC FIELDS; ELECTRONS; PHOTOCONDUCTIVITY; PHOTOSENSITIVITY; QUANTUM EFFICIENCY; SELENIUM; STABILITY; VISIBLE RADIATION