Researchers develop a polymer film that reduces defects in perovskites

Researchers at the University of California, Los Angeles have used a polymer film to reduce defects in the light-absorbing perovskite, producing solar cells that are efficient and relatively robust.

Researchers develop a polymer film that reduces defects in perovskites image

The team explains that perovskites usually used in solar cells typically contain an organic cation and lead halide anions. But the heat treatment used to convert the perovskite’s precursors into a crystalline layer can also drive out some of these organic cations. This leaves defects in the material’s structure that hamper its performance and potentially make it less stable to moisture, heat, and even sunlight itself.

Collaborative team focuses on MA to better understand perovskite PV stability issues

Researchers from the University of Fribourg and École Polytechnique Fédérale de Lausanne in Switzerland, Pandit Deendayal Petroleum University in India and Benemérita Universidad Autónoma de Puebla in Mexico have revealed new clues about the stability of perovskite thin films and solar cells.

“Our chief aim is to stabilize perovskite solar cells for many years and decades,” explains Michael Saliba, principal investigator at the Adolphe Merkle Institute, University of Fribourg. “Without long-term stability, any commercialization efforts will fail.”

Lead-free halide double perovskites successfully made to emit warm white light

Researchers at Huazhong University of Science and Technology (HUST) in China, University of Toledo in the U.S, Monash University in Australia, Jilin University and Tsinghua University in China, the Dalian Institute in China and the University of Toronto in Canada have examined a lead-free double perovskite that exhibited stable and efficient white light emission. In its mechanism of action, the material produced self-trapped excitons (STEs) due to Jahn-Teller distortion of the AgCl6 octahedron in the excited state of the complex, observed when investigating exciton-phonon coupling in the crystal lattice.

Lead-free halide double perovskites successfully made to emit warm white light image

The research team stated that a fifth of global electricity consumption is based on lighting, and efficient and stable white-light emission with single materials is ideal for such applications. Photon emission that covers the entire visible spectrum is, however, difficult to attain with a single material. Metal halide perovskites, for instance, have outstanding emission properties but contain lead, and so yield unsatisfactory stability. The perovskite in this study is, therefore, lead-free.

German team develops new process for perovskite solar cells with improved stability

Scientists at the Martin Luther University of Halle Wittenberg have investigated a new process for perovskite solar cell production, which they say could allow for creation of perovskite thin film layers with better long-term stability than others have achieved.

German team develops new process for perovskite solar cells with improved stability image

The process, co-evaporation, is already widely used in other industries. It consists of heating precursor materials in a vacuum, until they evaporate, and then growing a layer of crystals onto a colder glass substrate.

Cambridge team sets new efficiency record for perovskite LEDs

Researchers at the University of Cambridge have announced a new efficiency record for LEDs based on perovskite semiconductors, reportedly rivaling that of the best organic LEDs (OLEDs).

The team stated that compared to OLEDs, which are widely used in high-end consumer electronics, the perovskite-based LEDs can be made at much lower costs, and can be tuned to emit light across the visible and near-infrared spectra with high color purity.