Jordi Martorell and co-workers propose ways to achieve a long lifetime of polymer solar cells by addressing the issue and mechanism of UV-induced nano-morphology disorder. To increase device lifetime, the authors turned to thermal annealing prior to light soaking to increase the active layer’s crystalline order. The study predicts an impressive lifetime of 10 years for vertical applications and demonstrates that alongside the high power conversion efficiency of the cells, the strategy may be used in solar window technologies. To read the full article in Advanced Energy Materials, please visit: https://doi.org/10.1002/aenm.201701201