Synergistic reflective back contact and absorber engineering for high-efficiency ultrathin Cu(In,Ga)Se 2 solar cells
Abstract Ultrathin Cu(In,Ga)Se 2 (CIGS) solar cells offer a promising route to reducing material consumption while maintaining the advantages of high-efficiency thin-film photovoltaics.However, reducing the absorber thickness leads to incomplete light absorption and limits device performance. Here, we develop a reflective back contact (RBC) architecture to enhance light trapping in a 600 nm-thick CIGS absorber. Device performance was further improved by tailoring the CIGS deposition process and applying a 15 min RbF post-deposition treatment, leading to enhanced optoelectronic properties. The resulting devices reach a power conversion efficiency of 15.8%, which, to the best of our knowledge, represents the highest reported efficiency for a CIGS solar cell with an absorber thickness of approximately 600 nm. These results demonstrate a pathway to high-efficiency ultrathin CIGS solar cells through the combination of optical engineering, alkali treatment, and absorber growth control.
Authors
- Vincent Dufoulon
- Thomas Tom (ORCID: https://orcid.org/0000-0001-8436-6728)
- Nathanaëlle Schneider (ORCID: https://orcid.org/0000-0001-7749-2400)
- Damien Coutancier (ORCID: https://orcid.org/0009-0000-6109-9575)
- Amelle Rebaï (ORCID: https://orcid.org/0009-0006-4822-1349)
- Stéphane Collin (ORCID: https://orcid.org/0000-0001-6176-1653)
- Negar Naghavi (ORCID: https://orcid.org/0000-0002-6045-5096)
- Jackson Lontchi (ORCID: https://orcid.org/0000-0002-6155-5945)
- Javid Hajhemati (ORCID: https://orcid.org/0009-0004-0504-7729)
- Emilee Fortier (ORCID: https://orcid.org/0000-0002-5031-4978)
- Peggy Marie
- Stéfania Cacovich (ORCID: https://orcid.org/0000-0002-6402-4816)
- Yixuan Fu (ORCID: https://orcid.org/0009-0007-2784-0551)
- Loukiana Kozlov (ORCID: https://orcid.org/0009-0002-2043-0641)
Institutions
- Centre National de la Recherche Scientifique (FR)
- École Polytechnique (FR)
- Chimie ParisTech - PSL (FR)
- Centre de Nanosciences et de Nanotechnologies (FR)
- Institut Polytechnique de Paris (FR)
- Institut Photovoltaïque d’Île-de-France (FR)
Publication Details
- Journal
- Journal of Physics Energy
- Published
- 2026-11-09
- DOI
- https://doi.org/10.1088/2515-7655/aebfc7
- Primary Topic
- Chalcogenide Semiconductor Thin Films
- Type
- article
- Field-Weighted Citation Impact
- 0.00