A collaboration between KAUST and Oxford University researchers has designed a strategy that grows perovskites into centimeter-scale, highly pure crystals thanks to the effect of surface tension. In their natural state, perovskites have difficultly moving solar-generated electricity because they crystallize with randomly oriented grains. The team is working on ways to speed up the flow of these charge carriers using inverse temperature crystallization (ITC) - a technique that uses special organic liquids and thermal energy to force perovskites to solidify into structures resembling single crystals (the optimal arrangements for device purposes).

While ITC produces high-quality perovskites far faster than conventional chemical methods, the intriguing mechanisms that initiate crystallization in hot organic liquids are poorly understood. The team recalls spotting a key piece of evidence during efforts to adapt ITC toward large-scale manufacturing. "At some point, we realized that when crystals appeared, it was usually at the solution's surface," the researchers said. "And this was particularly true when we used concentrated solutions".

Researchers from the Swiss Ecole Polytechnique Fédérale de Lausanne (EPFL) report the "highest stability levels for CuSCN perovskite to date". The cells retained 95% of their initial stability, with an efficiency level of 20%. The researchers, using a thin layer of reduced graphene oxide, manages to get the performance of the perovskite solar cells to drop by less than 5% when the cells were placed under 60°C sunlight for more than 1000 hours.

The EPFL scientists have concluded that CuSCN stands out as a stable, efficient and cheap option. However, earlier research has produced only moderate efficiency and stability improvements. In order to resolve these issues, the team developed a simple dynamic solution-based method for depositing highly conformal, 60-nm thick CuSCN layers. This facilitates the construction of perovskite cells with stabilized power-conversion efficiencies above 20%.

Researchers at Clemson University in South Carolina received two new grants that together total more than $1 million for researching related to nuclear energy, in which they will focus on perovskite materials.

One of the researchers will be working on ways to dispose of tritium, a radioactive byproduct of nuclear reactors that makes its way through the ecosystem into the water and food supply, posing a radioactive health hazard if ingested. The goal is to develop a membrane similar to an air or oil filter that would separate tritium from the water that is used in creating nuclear energy. Another scientists' grant pays for a specialty microscope that will be the only one of its kind in South Carolina. Collaborators are involved in both projects. The researchers will experiment with different materials in the form of powders, primarily focusing on the naturally occurring mineral perovskite.

Oxford Photovoltaics is to receive financing from the European Investment Bank (EIB) for its planned pilot site in Germany. The bank is considering providing EUR 15 million ($17.6 million USD) for the project, which will turn an existing PV thin-film module factory in Germany into a "first-of-its-kind" plant for the production of tandem silicon-perovskite PV cells.

According to EIB, the site will allow the company to demonstrate its perovskite technology at full wafer scale in pilot volumes and deploy perovskite on silicon tandem cells. The total cost of the project is EUR 30 million.

A team of researchers from The Hebrew University of Jerusalem in Israel, led by Dr. Lioz Etgar, investigated the optical and physical properties of bromide quasi 2D perovskites synthesized using different barrier molecules. The team reports on the high power conversion efficiency (PCE) and high open circuit voltage (V_oc) of bromide-based quasi 2D perovskite solar cells.

The various bromide quasi 2D perovskites were introduced into two PV cell configurations (with and without HTM). The use of the quasi 2D perovskite as an absorbing layer in PSCs reportedly yields improved efficiencies and open circuit voltage as compared to 3D PSCs. Different barriers in the quasi 2D structures have been shown to affect the photovoltaic performance; the cells' performance is reduced when increasing barrier length. However, the perovskite's hydrophilic character is suppressed with an increase in the chain length of the barrier molecule.