Thin Ag Precursor Layer-Assisted Co-Evaporation Process for Lowerature Growth of Cu(In,Ga)Se2 Thin Film

Gayeon Kim, Won Mok Kim, Jong Keuk Park, Donghwan Kim, Hyeonggeun Yu, Jeung Hyun Jeong

Research output: Contribution to journalArticle

2 Citations (Scopus)

Abstract

Achieving favorable band profile in lowerature-grown Cu(In,Ga)Se2 thin films has been challenging due to the lack of thermal diffusion. Here, by employing a thin Ag precursor layer, we demonstrate a simple co-evaporation process that can effectively control the Ga depth profile in CIGS films at low temperature. By tuning the Ag precursor thickness (â¼20 nm), typical V-shaped Ga gradient in the copper indium gallium diselenide (CIGS) film could be substantially mitigated along with increased grain sizes, which improved the overall solar cell performance. Structural and compositional analysis suggests that formation of liquid Ag-Se channels along the grain boundaries facilitates Ga diffusion and CIGS recrystallization at low temperatures. Formation of a fine columnar grain structure in the first evaporation stage was beneficial for subsequent Ga diffusion and grain coarsening. Compared to the modified co-evaporation process where the Ga evaporation profile has been directly tuned, the Ag precursor approach offers a convenient route for absorber engineering and is potentially more applicable for roll-to-roll fabrication system.

Original languageEnglish
Pages (from-to)31923-31933
Number of pages11
JournalACS Applied Materials and Interfaces
Volume11
Issue number35
DOIs
Publication statusPublished - 2019 Sep 4

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Keywords

  • Ag precursor
  • CIGS
  • Ga profile
  • lowerature process
  • thin-film solar cell

ASJC Scopus subject areas

  • Materials Science(all)

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