The Perovskite-Info newsletter (December 7, 2021)

Researchers at the National Renewable Energy Laboratory (NREL), along with collaborators from the SLAC National Accelerator Laboratory, University of Toledo, Princeton University, University of Arizona, University of Kentucky, and University of Colorado, have found away to improve the efficiency of perovskite solar cells by as much as 16%.

The effort involved combining a two-dimensional (2D) perovskite layer with a three-dimensional (3D) perovskite layer, which yielded a solar cell with improvements in both efficiency and stability.

Researchers at Nankai University in China have developed a Dion-Jacobson (DJ) two-dimensional perovskite solar cell. They claim it exhibits a power conversion efficiency of 18.82%, as well as remarkable light, thermal, environmental, and operational stability.

Two-dimensional (2D) Dion-Jacobson (DJ) phase perovskites have sparked interest in the scientific community due to their stability against harsh environmental conditions and their competitive performance in optoelectronic applications. Solar cells based on DJ perovskites, however, tend to show comparatively poor performance compared to their 3D counterparts.

In a joint collaborative effort between the University of Pavia in Italy and the Technische Universität Dresden in Germany, researchers have developed a novel method to significantly improve the efficiency of inverted architecture perovskite solar cells.

The method is based on a modification of the interfaces of the perovskite active layer by introducing small amounts of organic halide salts at both the bottom and the top of the perovskite layer. Such organic halide salts, typically used for the formation of two-dimensional perovskites, led to the suppression of microstructural flaws and passivation of the defects of the perovskite layer. Using this approach, the team has achieved a power conversion efficiency of 23.7%, which they say is the highest reported to date for an inverted architecture perovskite solar cell.

An international research team from TU Dort­mund Uni­ver­sity, the Russian Academy of Sciences and ETH Zürich has dis­cov­ered that the electron dynamics in perovskite crystals are largely determined by lead. This discovery suggests that replacing this element could enable better control of the crystals’ material properties.

TU Dort­mund Uni­ver­sity Professor Dmitri Yakovlev's group investigated ultrafast interaction processes between optically excited charge carriers and their surroundings in perovskite crystals. The team was able to show that the magnetic properties can be regulated on an ultrafast time scale through the use of optical pulses with a duration of trillionths of a second. This proof that they can be con­trolled is of particular interest for possible new applications.

A research team led by Erkan Aydin and Stefaan De Wolf from the KAUST Solar Center, along with co-authors from Turkey, the Netherlands and Spain, has presented an overview on the process of stopping damage from occurring to devices during the creation of transparent electrodes, particularly for a technique known as sputtering.

Damage from adding electrical contacts to sensitive semiconductors, including perovskites, can be mitigated using a buffer layer and optimized deposition. The new review gives a comprehensive overview for the origin and mitigation strategies for this technological problem.