Electrical properties of Ga2O3: Sn/CIGS hetero-junction

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

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

Abstract

There is an increased need for highly sensitive imaging devices to develop high resolution and high speed image sensors. Incident light intensity per pixel of image sensors is getting lower because the pixel resolution and frame rate of image sensors are becoming higher. We investigated the feasibility of using a photoconductor with tin-doped gallium oxide (Ga2O 3:Sn)/Cu(In,Ga)Se2 (CIGS) hetero-junction for visible light image sensors. CIGS chalcopyrite thin films have great potential for improving the sensitivity of image sensors and CIGS chalcopyrite semiconductors have both a high absorption coefficient and high quantum efficiency. Moreover, the band gap can be adjusted for visible light. We applied Ga2O3 as an n-type semiconductor layer and a hole-blocking layer to CIGS thin film to reduce the dark current. The experimental results revealed that dark current was drastically reduced due to the application of Ga2O3 thin film, and an avalanche multiplication phenomenon was observed at an applied voltage of over 6 V. However, non-doped Ga2O3/CIGS hetero-junction only had sensitivity in the ultraviolet light region because their depletion region was almost completely spread throughout the Ga 2O3 layer due to the low carrier density of the Ga 2O3 layer. Therefore, we used Ga2O 3:Sn for the n-type layer to increase carrier density. As a result, the depletion region shifted to the CIGS film and the cells had sensitivity in all visible regions. These results indicate that Ga2O 3:Sn/CIGS hetero-junction are feasible for visible light photoconductors.

Original languageEnglish
Title of host publicationMaterials Research Society Symposium Proceedings
PublisherMaterials Research Society
Volume1603
DOIs
Publication statusPublished - 2014
Event2013 JSAP-MRS Joint Symposia - Kyoto, Japan
Duration: 2013 Sep 162013 Sep 20

Other

Other2013 JSAP-MRS Joint Symposia
CountryJapan
CityKyoto
Period13/9/1613/9/20

Fingerprint

Image sensors
Electric properties
electrical properties
sensors
Photoconducting materials
photoconductors
Dark currents
dark current
Thin films
Carrier concentration
sensitivity
depletion
thin films
Pixels
pixels
Semiconductor materials
gallium oxides
n-type semiconductors
Tin
Gallium

Keywords

  • photoconductivity
  • semiconducting
  • sensor

ASJC Scopus subject areas

  • Materials Science(all)
  • Condensed Matter Physics
  • Mechanical Engineering
  • Mechanics of Materials

Cite this

Kikuchi, K., Imura, S., Miyakawa, K., Kubota, M., & Ohta, E. (2014). Electrical properties of Ga2O3: Sn/CIGS hetero-junction. In Materials Research Society Symposium Proceedings (Vol. 1603). Materials Research Society. https://doi.org/10.1557/opl.2014.299

Electrical properties of Ga2O3 : Sn/CIGS hetero-junction. / Kikuchi, Kenji; Imura, Shigeyuki; Miyakawa, Kazunori; Kubota, Misao; Ohta, Eiji.

Materials Research Society Symposium Proceedings. Vol. 1603 Materials Research Society, 2014.

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

Kikuchi, K, Imura, S, Miyakawa, K, Kubota, M & Ohta, E 2014, Electrical properties of Ga2O3: Sn/CIGS hetero-junction. in Materials Research Society Symposium Proceedings. vol. 1603, Materials Research Society, 2013 JSAP-MRS Joint Symposia, Kyoto, Japan, 13/9/16. https://doi.org/10.1557/opl.2014.299
Kikuchi K, Imura S, Miyakawa K, Kubota M, Ohta E. Electrical properties of Ga2O3: Sn/CIGS hetero-junction. In Materials Research Society Symposium Proceedings. Vol. 1603. Materials Research Society. 2014 https://doi.org/10.1557/opl.2014.299
Kikuchi, Kenji ; Imura, Shigeyuki ; Miyakawa, Kazunori ; Kubota, Misao ; Ohta, Eiji. / Electrical properties of Ga2O3 : Sn/CIGS hetero-junction. Materials Research Society Symposium Proceedings. Vol. 1603 Materials Research Society, 2014.
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