A group of chemists at Kaunas University of Technology (KTU), Lithuania, together with the physicists from Vilnius University and the Swiss Federal Institute of Technology, Lausanne (EPFL), have uncovered one of the possible reasons behind the short lifespan of perovskite solar cells and have offered solutions. According to the scientists, hole transporting materials used in perovskite solar cells are reacting with one of the most popular additives, tert-butylpyridine, which has a negative impact on overall device performance.