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Title: Quantum dot Ge/TiO{sub 2} heterojunction photoconductor fabrication and performance

Spun cast TiO{sub 2}-Ge quantum dot (QD) heterojunction type photodetectors have been fabricated and characterized, with interest paid to photocurrent enhancements related to device design. Performance as a function of absorber layer thickness, QD size, and back contact is investigated. We have achieved ultra-thin (∼200 nm) devices with photocurrents at 0.5 V of 10{sup −4} A cm{sup −2} while the thickest devices have photocurrents at 0.5 V of 10{sup −2} A cm{sup −2} with on-off ratios >100, which represents 5 orders of magnitude increase in photocurrents over previously fabricated Ge QD devices. At 0.5 V bias, the currents in our devices are competitive with thin-film Ge photovoltaics.
Authors:
;  [1] ; ;  [2] ;  [3]
  1. Department of Physics, University of California Santa Cruz, Santa Cruz, California 95064 (United States)
  2. Department of Chemistry, University of California Davis, Davis, California 95616 (United States)
  3. Key Laboratory of Interface Science and Engineering in Advanced Materials of Ministry of Education, Taiyuan University of Science and Technology, Taiyuan, Shanxi 030024 (China)
Publication Date:
OSTI Identifier:
22253965
Resource Type:
Journal Article
Resource Relation:
Journal Name: Applied Physics Letters; Journal Volume: 103; Journal Issue: 22; Other Information: (c) 2013 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY; EQUIPMENT; FABRICATION; HETEROJUNCTIONS; PERFORMANCE; PHOTOCURRENTS; PHOTODETECTORS; PHOTOVOLTAIC EFFECT; QUANTUM DOTS; THICKNESS; THIN FILMS; TITANIUM OXIDES