Perovskite News - Page 1

Physicists at the École polytechnique fédérale de Lausanne (EPFL) in Switzerland have used perovskite materials to alter a magnetic bit’s polarity with light, potentially opening the door to denser and faster disk drives using magneto-optical technology.

Researchers László Forró, Bálint Náfrádi, Péter Szirmai and Endre Horváth suggest magneto-optical drives using this method could be physically smaller, faster and cheaper than today’s disk drives. They also say it is an alternative to heat-assisted magnetic recording (HAMR).

Researchers at The Australian National University (ANU) have announced an impressive achievement - a silicon/perovskite tandem solar cell with a conversion efficiency of 27.7%.

Professor Kylie Catchpole says this would only need to improve slightly - to around 30% - before the technology could be rolled out around the world. "In comparison, typical solar panels being installed on rooftops at the moment have an efficiency around 20%" Professor Catchpole said.

A team of researchers at EPFL collaborated with the Swiss National Supercomputing Center (referred to as CSCS) to gain a better understanding of the physics behind perovskites' photovoltaic performance, that may facilitate the design of new materials with favorable properties in the future.

The results of the simulations on “Piz Daint”: The image on the left shows the spatial arrangement of the electron holes (magenta); the one on the right shows the location of the extra electrons (green). (Image: Francesco Ambrosio)

The researchers used the “Piz Daint” supercomputer at CSCS to investigate a perovskite material called methylammonium triiodoplumbate (CH₃NH₃PbI₃) — a material that can harvest sunlight with excellent efficiency because of a vital property: the exceptionally long lifetime of its charge carriers.

Researchers from Colorado University in Boulder with the US Department of Energy’s National Renewable Energy Laboratory (NREL) have shown how a change in chemical composition managed to boost the longevity and efficiency of a perovskite solar cell.

The new formula reportedly enabled the solar cell to resist a stability problem that has so far thwarted the commercialization of perovskites. The problem is known as light-induced phase-segregation, which occurs when the alloys that make up the solar cells break down under exposure to continuous light.

Researchers from Peking University in China have developed a manufacturing method for perovskite solar cells using a pre-nucleation technique. Compared to traditional solvent dripping methods, the approach enables the creation of smaller crystallites in the perovskite films as uncontrolled crystallite growth affects the efficiency and durability of cells.

The technique aims to avoid the efficiency loss caused by humidity linked to the interactions of ambient water and oxygen with the perovskite precursors and substrate used during cell production.

Italian researchers from two Italian institutions claim to have developed a two-terminal tandem perovskite-silicon solar cell with a conversion efficiency 26.3%.

The researchers added graphene to the titanium dioxide electron selective layer used in a perovskite solar cell to increase chemical stability. The two-terminal cell was made by stacking two sub-cells which were fabricated and optimized separately. The new device blends the advantages of thin-film perovskite and silicon-based heterojunction cells, according to its developers.

KAIST researchers have designed a method to make perovskite crystals at lower temperatures, that could lead the way towards lower-cost solar cells by eliminating defects that reduce efficiency.

Most current work on perovskite solar cells focuses on polycrystalline versions, where the efficiency record is 25%, say Omar Mohammed and Osman Bakr, materials scientists at King Abdullah University of Science and Technology. But polycrystalline films are only a few hundred nm thick, whereas single crystals can be grown to approximately 20 µm. The thicker films can absorb more light so single-crystal solar cells could prove to be superior. The problem is that so far, single-crystal lead perovskite solar cells don’t reach 20% efficiency.