Researchers at the Japan-based Okinawa Institute of Science and Technology Graduate University (OIST) have developed perovskite-based solar devices using a new perovskite material that is stable, efficient and relatively cheap to produce.

This material has several key features. First, it is completely inorganic – an important shift, because organic components are usually not thermostable and degrade under heat. Since solar cells can get very hot in the sun, heat stability is crucial. By replacing the organic parts with inorganic materials, the researchers made the perovskite solar cells much more stable. “The solar cells are almost unchanged after exposure to light for 300 hours,” says Dr. Zonghao Liu, an author on the paper.

Researchers at the Argonne-Northwestern Solar Energy Research Center (ANSER) have developed a new way to protect perovskite-based solar cells from water and stabilize them against heat. By carefully growing an ultrathin layer of metal oxide on a carbon coating, the researchers made a perovskite device that worked even after exposing it to a stream of water.

Solar cells are made up of layers, each with a specific duty. The perovskite layer absorbs sunlight, which can excite an electron. The electron could go back to where it started, unless it can be successfully extracted out of the absorbing layer quickly. For this device, the researchers placed a layer of PC61BM, a carbon-based material, on top of the perovskite, which has two roles.