Solar Cells (IMAGE) Aalto University Caption In studies on the ageing of perovskite solar cells and the dye cells in the picture, a sufficiently large number of samples is one of the prerequisites for quality. Credit Valeria Azovskaya, Materials Platform, Aalto University. 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.