Researchers use improved gas quenching technique for highly efficient perovskite solar cells

A team of researchers, led by the University of Sydney, have used a new approach that could be the key to producing low cost and environmentally friendly perovskite solar cells, while achieving a new efficiency milestone for these cells.

The researchers said they had made crucial improvements to the process of ‘gas quenching’ to fabricate perovskite thin films. The research team successfully demonstrated a steady-state conversion efficiency of 23.6%, which they claim is the highest efficiency achieved for perovskite solar cells produced using the ‘gas quenching’ technique.

Researchers design stable inverted perovskite solar cells with 22.1% efficiency using a star-shaped polymer

Researchers at the Swiss Federal Institute of Technology in Lausanne (EPFL) and Northwestern Polytechnical University in China have fabricated an inverted perovskite solar cell based on a star-shaped polymer that can reportedly improve charge transport and inhibit ion migration at the perovskite interface.

Inverted perovskite solar cell with 22.1% efficiency via star-shaped polymer imageSchematic diagram of the interaction between the PPP polymer (partial 3D structure) and perovskite. Image from ScienceAdvances

The cell has a “p-i-n” layout and is based on a perovskite material known as CsMAFA modified with a polymer called polyhedral oligomeric silsesquioxane-poly(trifluoroethyl methacrylate)-b-poly(methyl methacrylate) or simply PPP polymer.

Researchers break efficiency record with flipped perovskite-silicon tandems

Researchers from King Abdullah University of Science and Technology (KAUST) in Saudi Arabia, in collaboration with University of Toronto, the National University of Singapore and National Technical University of Athens, have designed monolithic tandem solar cell with power conversion efficiency of 27%, surpassing the previous best reported value of 22% in the same configuration.

Flipped perovskite-silicon tandems break a new record image

The team explains that translating the high power conversion efficiencies of single-junction perovskite solar cells in their classic, non-inverted (n–i–p) architecture to efficient monolithic n–i–p perovskite/silicon tandem solar cells with high current densities has been a persistent challenge due to the lack of low-temperature processable, chemically-insoluble contact materials with appropriate polarity and sufficient optical transparency. To address this, they developed sputtered amorphous niobium oxide (a-NbOx) with ligand-bridged C60 as an efficient electron-selective contact, deposited on the textured-silicon bottom cell.

Pre-synthesized perovskite material reduces defects and improves solar cell performance

researchers at the Okinawa Institute of Science and Technology Graduate University (OIST), led by Professor Yabing Qi, have demonstrated that creating a raw material used for perovskite solar cells in a different way could be key to the success of these cells.

Pre-synthesized crystalline perovskites improves PSCs image

“There’s a necessary crystalline powder in perovskites called FAPbI3, which forms the perovskite’s absorber layer,” explained one of the lead authors, Dr. Guoqing Tong, Postdoctoral Scholar at OIST. “Previously, this layer was fabricated by combining two materials – PbI2 and FAI. The reaction that takes place produces FAPbI3. But this method is far from perfect. There are often leftovers of one or both of the original materials, which can impede the efficiency of the solar cell.”

Researchers use thermal evaporation to achieve 15% efficient 'black perovskite' solar cells

Researchers at the Dresden University of Technology (TUD) have announced the fabrication of a solar cell based on all-inorganic cesium-lead iodide (CsPbI3) perovskite, which is also sometimes referred to as 'black perovskite'.

Black perovskite solar cell with 15% efficiency via thermal evaporation imagea) Schematic of the deposition procedure (b) device structure. Image from Advanced Energy Materials

TUD researcher Yana Vaynzof said that the choice of this specific material was motivated by the fact that it shows superior stability as compared to the commonly used organic-inorganic lead halide perovskites.