Flexible semi-transparent tandem perovskite/CIGS solar cell with 26.5% efficiency reported by Solliance and MiaSolé

Solliance and U.S-based MiaSolé announced a new record - power conversion efficiency of 26.5% on a tandem solar cell that combined a top rigid semi-transparent perovskite solar cell with a bottom flexible copper indium gallium selenide (CIGS) cell.

Solliance and Miasole's 23%efficiency tandem perovskite/CIGS cells image

This impressive efficiency was achieved by optimizing the bandgap and the efficiency of both the rigid semi-transparent perovskite top cell and the flexible CIGS bottom cell. The CIGS was roll to roll produced on steel foil, with a power conversion efficiency of 20.0%.

A simple dual passivation approach improves tin-based perovskite solar cells

Scientists at Shaanxi Normal University in China have demonstrated a new, simpler technique for manufacturing tin-containing perovskite solar cells (PSCs).

To improve PSC device stability, researchers tend to focus on improving either the perovskite layer or the tin-based electron transport layer (ETL) of the PSC. The new research, however, uses a new dual passivation technique that stabilizes both tin in the ETL and elements in the perovskite film in one step.

Researchers reconfigure the band-edge states of perovskites to enhance their performance

Researchers from UCLA, NREL, The University of Toledo, Yangzhou University, Soochow University, Monash University and Lawrence Berkeley National Laboratory, have found that perovskites have a previously unutilized molecular component that can further tune the electronic property of perovskites.

perovskite material with organic molecules that can add to its electronic properties imageSchematic of perovskite material with organic molecules that can add to its electronic properties. Credit: Jingjing Xue and Rui Wang/UCLA Samueli School of Engineering

Perovskite materials have a crystal-lattice structure of inorganic molecules like that of ceramics, along with organic molecules that are interlaced throughout. Up until now, these organic molecules appeared to only serve a structural function and would not directly contribute to perovskites' electronic performance.

Dual Passivation technique yields perovskite solar cells with 20.14% efficiency

Researchers from the Shaanxi Normal University in China have designed a perovskite solar cell based on methylammonium lead iodide (MAPbI3) through a dual passivation technique that simultaneously passivates trap defects in both the perovskite and electron transport layer (ETL) films.

“So far, most techniques for modifying perovskite solar cells focus on either the perovskite or electron transport layer,” the research group reported, noting that the ETL must have decent optical transmittance and high electron mobility to extract photo‐induced carriers and contribute to the solar cell efficiency.

ANU researchers explain the methods that helped them reach record PSC efficiency

In a study announced last August, researchers from the Australian National University (ANU) reached an impressive 21.6% efficiency, which they said is the highest achieved for perovskite cells above a certain size. The details of their work, and the techniques used by the research team to achieve the results, have now been explained.

Lead researcher, associate professor Tom White, said the research team achieved the new record by adapting a technique previously used with traditional silicon-based solar cells that removed defects. “A common problem with solar cells is that any defects in the cell can trap electrons, taking away the energy they gained by absorbing sunlight,” associate professor White said. “A way around this is to “passivate” the surface by coating the light absorbing material with a thin layer of another material to reduce defects. But the materials used to reduce defects are often poor conductors of electricity.”