Perovskite (IMAGE) DOE/Los Alamos National Laboratory Caption Three types of large-area solar cells are made out of two-dimensional perovskites. At left, a room-temperature cast film; upper middle is a sample with the problematic band gap, and at right is the hot-cast sample with the best energy performance. Credit Los Alamos National Laboratory Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.