The Korea Institute of Energy Research (KIER) reportedly achieved a certified efficiency of 26.7% for perovskite/CIGS tandem solar cells on September 1. The figure was certified by the Fraunhofer Institute for Solar Energy Systems in Germany and was reportedly added to the National Renewable Energy Laboratory (NREL)'s chart of record efficiencies by solar-cell type.
Key Change
The new record is 0.4 percentage points higher than the 26.3% efficiency achieved in 2025 by a joint research team from Seoul National University and the Korea Institute of Science and Technology in the same perovskite/CIGS thin-film tandem solar-cell field.
The key figure is 26.7%. However, it should be understood as a certified efficiency record for a research-stage cell.
Current Status
Tandem solar cells combine layers of solar cells that absorb different wavelength ranges of light. In this technology, perovskite is placed on top and CIGS underneath.
KIER researchers said they reduced interfacial and optical losses by optimizing the interlayer materials and processes, as well as the structures of the top transparent electrode and charge-transport layer. Because perovskite/CIGS thin-film structures are lightweight and flexible, they are being considered for applications such as buildings, vehicles, and small satellites, where weight and installation area are important constraints.
Meanwhile, the Gwangju Institute of Science and Technology (GIST) announced that it held a kickoff meeting on August 31 for a council promoting the commercialization of perovskite solar cells and began building a cooperation framework. The council is expected to operate through the following four specialized divisions:
- Technology
- Certification and standards
- Industrialization
- Investment
GIST said each division would consist of approximately five to seven members and that it plans to expand the council to around 30 members by including experts from industry, academia, research institutions, and specialized organizations.
Impact
The 26.7% record indicates that the research performance of tandem solar cells combining perovskite and CIGS has improved over the previous record. Since lightweight and flexible thin-film structures are being considered for potential applications, the result may serve as an indicator for tracking technology developments in buildings, vehicles, and small satellites.
However, an efficiency record alone does not mean commercialization is complete. Before actual product applications, the following points still need to be assessed:
- Feasibility of large-area module production
- Long-term durability
- Process reproducibility
- Economic viability
- Certification and standardization
What to Watch Next
Going forward, it will be important to check the measurement conditions and record scope under which the 26.7% figure was listed, whether research-cell performance can be maintained in large-area modules, and which industrialization and certification challenges the GIST council makes more specific through its four divisions.
Sources checked:
- ETNews, “Next-generation thin-film solar cell achieves highest efficiency: KIER sets successive records, demonstrating Korea’s technological competitiveness”: https://www.etnews.com/20260901000051
- TJB, “Breaking through the limits of silicon solar cells… What enabled KIER to set a new world-record efficiency?”: https://www.tjb.co.kr/news05/bodo/view/id/103049/version/1
- Chungcheong News, “KIER sets a new world-record efficiency in next-generation tandem solar cells”: https://www.ccnnews.co.kr/news/articleView.html?idxno=414235
- Gwangju Institute of Science and Technology, “GIST launches a council to promote commercialization of perovskite solar cells”: https://ewww.gist.ac.kr/kr/html/sub06/060104.html?GotoPage=8&mode=V&no=221919
- ETNews, “GIST launches a council to promote commercialization of perovskite solar cells and appoints chairs for four divisions”: https://www.etnews.com/20260901000060
- Seoul National University, “New photovoltaic performance record achieved for thin-film tandem solar cells”: https://www.snu.ac.kr/research/highlights?bbsidx=156472&md=v
The sources above were checked on September 1, 2026.