KIER Achieves World Record 26.7% Efficiency for Perovskite/CIGS Tandem Solar Cells, Paving Way for Space, Automotive, BIPV Applications

September 13, 2026

Compound Semiconductor South Korea

Overview

The Korea Institute of Energy Research (KIER) has set a new world record for perovskite/CIGS tandem solar cells, achieving 26.7% efficiency, as certified by Fraunhofer ISE and recognized by the US NLR. This breakthrough addresses efficiency losses through advanced interfacial layer materials and optimized transparent electrodes and charge transport layers. Focusing on a lightweight, flexible form factor, this technology is poised for applications in space, automotive, and building-integrated photovoltaics (BIPV).

In Depth

Key Findings: KIER Breaks World Record with 26.7% Efficient Perovskite/CIGS Tandem Solar Cell, Advancing Flexible PV for Diverse Applications

The Korea Institute of Energy Research (KIER) has achieved a new world record power conversion efficiency of 26.7% for perovskite/CIGS (copper-indium-gallium-selenide) tandem solar cells, a figure independently certified by the Fraunhofer Institute for Solar Energy Systems (ISE) and acknowledged by the US National Laboratory of the Rockies (NLR). This landmark accomplishment represents a significant milestone in the development of next-generation photovoltaic technology. Crucially, the technology’s inherent lightweight and flexible nature positions it for transformative applications in sectors previously challenging for traditional solar cells, including space, automotive, and building-integrated photovoltaics (BIPV).

Technical Details: Overcoming Efficiency Losses and Material Optimization

KIER’s research team successfully tackled major efficiency losses that typically plague perovskite/CIGS tandem solar cells through an innovative approach. At the core of this breakthrough is the development of advanced interfacial layer materials coupled with a meticulous optimization of the top transparent electrode and charge transport layer. The interfacial layer plays a critical role in facilitating efficient charge carrier transport between the perovskite and CIGS sub-cells while minimizing recombination losses. Previous devices often suffered from efficiency degradation due to defects at these interfaces, a challenge KIER has effectively overcome with its novel material design.

Specifically, improvements in the transmittance of the top transparent electrode and enhanced conductivity and stability of the charge transport layer were key drivers for boosting overall conversion efficiency. These optimizations allow for a broader range of the solar spectrum to be utilized effectively, ensuring that both the perovskite and CIGS layers perform at their maximum potential within their respective absorption bands. This technology effectively transcends the “heavy” and “rigid” limitations of conventional silicon solar cells, maximizing the benefits of lightweight and flexible thin-film photovoltaics.

Background and Application Potential

Perovskite solar cells are widely recognized for their high efficiency and low-cost potential but have faced challenges related to durability and lead content. CIGS solar cells, conversely, offer high stability and excellent performance but have been limited in efficiency. The tandem structure, combining both, leverages their respective strengths and mitigates weaknesses, leading to superior device performance. KIER’s achievement is particularly significant as it opens up possibilities for widespread adoption in innovative applications such as spacecraft, drones, electric vehicle roofs, and BIPV, where lightweight and aesthetic integration are paramount. The flexible form factor also simplifies retrofitting on existing structures, helping to accelerate renewable energy deployment in urban environments.

Strategic Significance and Outlook

This world record underscores South Korea’s emerging leadership in next-generation solar cell technology. KIER’s innovation is set to accelerate the commercialization of perovskite/CIGS tandem solar cells, potentially making a substantial impact on the global photovoltaic market. Researchers and engineers are expected to build upon these results, focusing on further improvements in stability, cost reduction, and scalable manufacturing techniques. For investors, the expanding market for lightweight and flexible solar cells presents new growth opportunities with KIER’s technology, stimulating further investment in sustainable energy solutions and positioning South Korea as a key innovator in the global clean energy transition.

Source: https://compoundsemiconductor.net/article/125336/Korean_team_sets_efficiency_record_for_perovskiteCIGS_tandem

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