Electrical properties of photoconductor using Ga2O 3/CuGaSe2 heterojunction

Kenji Kikuchi, Shigeyuki Imura, Kazunori Miyakawa, Misao Kubota, Eiji Ohta

Research output: Chapter in Book/Report/Conference proceedingConference contribution


The feasibility of using a photoconductor with a Ga2O 3/CuGaSe2 heterojunction for visible light sensors was investigated. CIGS chalcopyrite semiconductors have both a high absorption coefficient and high quantum efficiency. However, their dark current is too high for image sensors. In this study, we applied gallium oxide (Ga 2O3) as a hole-blocking layer for CIGS thin film to reduce the dark current. Experimental results showed that the dark current was drastically reduced, and an avalanche multiplication phenomenon was observed at an applied voltage of over 6 V. However, this structure had sensitivity only in the ultraviolet light region because its depletion region was almost completely spread in the Ga2O3 layer since the carrier density of the Ga2O3 layer was much lower than that of the CIGS layer. These results indicate that the Ga2O3/CuGaSe2 heterojunction has potential for use in visible light sensors but that we also need to increase the carrier density of the Ga2O3 layer to shift the depletion region to the CIGS film.

Original languageEnglish
Title of host publicationCompound Semiconductors
Subtitle of host publicationThin-Film Photovoltaics, LEDs, and Smart Energy Controls
Number of pages5
Publication statusPublished - 2013
Event2013 MRS Spring Meeting - San Francisco, CA, United States
Duration: 2013 Apr 12013 Apr 5

Publication series

NameMaterials Research Society Symposium Proceedings
ISSN (Print)0272-9172


Other2013 MRS Spring Meeting
Country/TerritoryUnited States
CitySan Francisco, CA

ASJC Scopus subject areas

  • General Materials Science
  • Condensed Matter Physics
  • Mechanics of Materials
  • Mechanical Engineering


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