Structural tuning of wide-gap chalcopyrite CuGaSe2 thin films and highly efficient solar cells: Differences from narrow-gap Cu(In,Ga)Se 2

Shogo Ishizuka, Akimasa Yamada, Paul J. Fons, Hajime Shibata, Shigeru Niki

Research output: Contribution to journalArticlepeer-review

56 Citations (Scopus)


Simultaneous realization of high values of open circuit voltage (V oc), fill factor (FF), and energy conversion efficiency (η) in wide-gap CuGaSe2 (CGS) solar cells has long been one of the most challenging issues in the realm of chalcopyrite photovoltaics. In this communication, structural tuning of CGS thin films by means of controlling the amount of Se flux used during CGS film growth and improvements in solar cell performance (Voc->-0.9-V, FF->-0.7, and η->-10%) are demonstrated. Systematic variations in CGS film properties with the Se flux and correlation with device properties are shown. The unique CGS thin-film growth kinetics, which are different from narrow-gap Cu(In,Ga)Se2, are also presented and discussed. This development of double digit efficiency for CGS solar cells opens a new frontier for the broad application of a new class of chalcopyrite-based devices.

Original languageEnglish
Pages (from-to)821-829
Number of pages9
JournalProgress in Photovoltaics: Research and Applications
Issue number7
Publication statusPublished - 2014 Jul
Externally publishedYes


  • Na effects
  • Se flux
  • chalcogenide
  • chalcopyrite

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Renewable Energy, Sustainability and the Environment
  • Condensed Matter Physics
  • Electrical and Electronic Engineering


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