Midsummer, a Swedish developer, in collaboration with researchers at the University of California, Los Angeles (UCLA), has developed a four-terminal perovskite-CIGS tandem solar cell that has demonstrated an efficiency of 24.9%.

Through a collaborative project with Yang of UCLA, Midsummer has showcased a four-terminal tandem solar cell that combines perovskite and CIGS technologies.

The ongoing research aims to create a two-terminal perovskite-CIGS cell, which would make this solar cell highly competitive and ideal for large-scale production.

This project demonstrates the possibility of constructing a tandem solar cell using Midsummer’s established production process and the Midsummer DUO machine.

The top cell of the tandem is a perovskite-based one that has been specifically optimized for seamless integration with Midsummer’s CIGS cells, which are utilized in the company’s range of commercial BIPV (Building Integrated Photovoltaics) products.

Yang said, “We are thrilled to have this opportunity to work with Midsummer and PMI. Our ultimate goal is to demonstrate two-terminal perovskite/CIGS tandem cells, suitable for mass production.”

The team said the newly developed solar cell has demonstrated impressive efficiency, which is achieved by combining a wide bandgap perovskite cell as the top layer and a CIGS cell as the bottom layer.

The DUO production system is designed to produce high-performance CIGS solar cells that can be made in dimensions of 156mm x 156mm on a flexible stainless-steel substrate.

“Integrating Midsummer’s production-proven CIGS processing with Yang’s Lab tailored perovskite shows a clear path toward expanding the reach of BIPV by improving efficiency and lowering costs,” said Leon Chiu, President of Pioneer Materials, Inc.

Sven Lindström, CEO of Midsummer, said perovskite-CIGS tandem cells have enormous potential for the future of solar energy, and Midsummer’s solar panel design is particularly well-suited for developing a commercial product for this type of solar panel.

One advantage of Midsummer’s design is that it includes a diode between each solar cell, which is an essential component for optimal efficiency in a tandem cell configuration. This feature is expected to give Midsummer’s design an edge in terms of commercial viability and potential for widespread use.

Recently, researchers at Helmholtz-Zentrum Berlin found that solar cells made of metal halide perovskites achieve high efficiencies and can be produced from liquid inks with little energy input.

In the same month, Italy-based renewable energy company Enel Green Power, researchers at the National Solar Energy Institute, and the French Alternative Energies and Atomic Energy Commission claimed to have achieved a power conversion efficiency of 26.5% for a 2-terminal tandem perovskite solar cell.