March 2020

The aging process of the perovskite solution used to fabricate solar cells makes the solution unstable, leading to poor efficiency and poor reproducibility of the devices. Reactants and preparation conditions also contribute to poor quality. To tackle these issues, a research team from the Qingdao Institute of Bioenergy and Bioprocess Technology (QIBEBT) of the Chinese Academy of Sciences (CAS) has studied the aging process of perovskite solution and proposed a way to avoid side reactions.

Prof. PANG Shuping, corresponding author of the paper, said "an in-depth understanding of fundamental solution chemistry had not kept up with rapid efficiency improvements in perovskite solar cells, even though such cells have been studied for 10 years... Normally, we need high temperature and a long time to fully dissolve the reactants, but some side reactions can happen simultaneously," said Prof. PANG. "Fortunately, we have found a way to inhibit them."

An international research team has developed a new type of solar cell that can both withstand environmental hazards and is 26.7% efficient in power conversion.

Structure and photovoltaic performance for the perovskite-Si tandem device. Image by KAIST

The researchers, led by Byungha Shin, a professor from the Department of Materials Science and Engineering at KAIST, focused on developing a new class of light-absorbing material, called a wide bandgap perovskite. The material has a highly effective crystal structure that can process the power needs, but it can become problematic when exposed to environmental hazards, such as moisture. Researchers have made some progress increasing the efficiency of solar cells based on perovskite, but the material reportedly has greater potential than what was previously achieved.

Germany-based in-situ metrology system maker LayTec has announced that its new InspiRe system applies high-speed in-situ reflectance measurements for monitoring perovskite thin-film formations during spin-coating and subsequent annealing.

In collaboration with professor Norbert Nickel's group at HZB, LayTec designed the InspiRe in-situ metrology system, which was applied to monitor both spin-coating and annealing. Gathering data at a time resolution on the millisecond scale allows resolving of the kinetics and phase formations during film formation.

Researchers at the Chinese Academy of Sciences (CAS) and other collaborators have reported a solution-processed broadband photodetector based on organic-inorganic hybrid perovskite and organic bulk heterojunction, achieving broadband response spectra up to 1000 nm with a high EQE in the NIR region, an ultrafast response speed of 5.6 ns and a wide linear dynamic range of 191 dB.

The team stated that thanks to the high-dynamic-range imaging capacity, high-quality visible-NIR actual imaging is obtained, enabling the accelerated translation of solution-processed photodetector applications from the laboratory to the imaging market.

Researchers from the University of Aberdeen have reported that a new family of chemical compounds known as 'hexagonal perovskites' could be extremely beneficial for ceramic fuel cell technology and reducing global carbon emissions.

Ceramic fuel cells are highly efficient devices that convert chemical energy into electrical energy and produce very low emissions if powered by hydrogen, providing a clean alternative to fossil fuels. Another advantage of ceramic fuel cells is that they can also use hydrocarbon fuels such as methane, meaning they can act as a 'bridging' technology which is an important asset in terms of the move away from hydrocarbons towards cleaner energy sources.

Researchers from Korea's Ulsan National Institute of Science and Technology (UNIST) developed a new perovskite-based catalyst that could enhance the charge-discharge performance of Metal-Air Batteries (MABs). MABs are very interesting as they are lightweight, affordable and has a large storage capacity, but current metal-based catalysts are too expensive for wide commercial adoption.

The new catalyst is made from a very thin layer of metal oxide film that is deposited on a surface of perovskite catalysts. This new so-called "composite catalyst" combines the two types of catalysts each with its own excellent performance for charging (metal) and discharging (the perovskite catalyst).

Scientists from the King Abdullah University of Science and Technology (KAUST) in Saudi Arabia and University of Toronto, have developed a perovskite-silicon tandem solar cell which they claim showed excellent operational stability under accelerated tests.

The device was made by combining solution-processed, micrometer-thick perovskite top cells with fully textured silicon heterojunction bottom cells.

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.