Material Selection through Accelerated Aging Enables >95% Performance Retention of a Perovskite–Silicon Tandem Solar Cell after 1 Year of Outdoor Monitoring

Abstract In order to ensure that the degradation modes of perovskite–silicon tandem solar cells exacerbated by accelerated aging tests are relevant to those observed under real-world operating conditions, accelerated testing should be developed in line with outdoor monitoring. Here, a short 3-day accelerated aging test under 1 sun equivalent illumination and at open-circuit conditions is validated by outdoor monitoring data. This accelerated test is used to successfully screen perovskite–silicon tandem cell architectures. In particular, by replacing 2-(9H-carbazol-9-yl)ethyl)phosphonic acid (2PACz) with nickel oxide (NiOx) combined with the dye N719 as the hole transport layer (HTL), significantly improved stability is achieved. Exemplifying this, after 1 year of maximum power point tracking outdoors, a tandem with the NiOx/N719 HTL retains 96.4% of its initial power conversion efficiency.