Absorber delamination-induced shunt defects in alcohol-based solution-processed Cu(In,Ga)(S,Se)2 solar modules

Yoon Mook Kang, Hae Seok Lee, Donghwan Kim, Seung Hoon Lee, Min Kyu Kim, Soohyun Bae, Jiyeon Nam, Hyun Jung Park, Sang Won Lee, Yun Jung Jang, Byoung Koun Min, Jung Yup Yang

Research output: Contribution to journalArticlepeer-review

3 Citations (Scopus)


Solution-processed chalcopyrite Cu(In,Ga)(S,Se)2 (CIGSSe) solar modules are promising alternatives to conventional crystalline silicon-based photovoltaic devices owing to their potential to lower production costs and compatibility with large-area flexible substrates. However, these modules typically exhibit a higher-than-expected cell-to-module loss, which, in most cases, is attributed to the emergence of critical shunt sites. In this study, we investigated the structural shunt defects induced by delamination of the absorber in alcohol-based solution-processed CIGSSe solar modules. Characterization with the use of lock-in thermography indicated that most of the delamination-induced shunt defects emerged locally near the patterned regions. Furthermore, secondary-ion mass spectroscopy measurements showed that, rather than being uniformly distributed, the alkali elements in the CIGSSe modules were concentrated near the patterned regions. The results revealed that the uniformity of this distribution is the key driving force behind absorber delamination. Finally, we confirmed that delamination-induced shunt defects can be alleviated by controlling the diffusion of alkali elements. Consequently, the energy conversion efficiency of the alcohol-based solution-processed CIGSSe solar modules was enhanced from 4.24 to 7.59% by introducing a layer that acts as a thin-film diffusion barrier.

Original languageEnglish
Pages (from-to)10384-10392
Number of pages9
JournalACS Applied Energy Materials
Issue number11
Publication statusPublished - 2020 Nov 23

Bibliographical note

Funding Information:
This work was supported by the New & Renewable Energy Core Technology Program of the Korea Institute of Energy Technology Evaluation and Planning (KETEP) and a financial grant from the Ministry of Trade, Industry & Energy, Republic of Korea (No. 20163010012570). This work was also supported by a National Research Foundation of Korea (NRF) grant funded by the Korean government (MSIT) (No. NRF-2020R1A2C1011815) and by the KU-KIST Graduate School Project.

Publisher Copyright:
© 2020 American Chemical Society


  • Absorber peel-off
  • Alkali element
  • CIGS solar module
  • Delamination
  • Lock-in thermography
  • Shunt defect
  • Solution-processed CIGS
  • Thin-film photovoltaics

ASJC Scopus subject areas

  • Chemical Engineering (miscellaneous)
  • Energy Engineering and Power Technology
  • Electrochemistry
  • Materials Chemistry
  • Electrical and Electronic Engineering


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