Improving the stability of inverted perovskite solar cells towards commercialization

Inverted perovskite solar cells (IPSCs) have great potential for commercialization, in terms of compatibility with flexible and multijunction solar cells. However, non-ideal stability limits their entry into the market. To shed light on the unstable origins of IPSCs, an analysis of recent research progress is needed. Here, we systematically discuss the stability of IPSCs, including each functional layer, interface and entire device, and consider environmental and operational stressors. We summarize a range of strategies for improving device stability and discuss the significance of stability test protocols. Finally, we highlight the shortcomings of current approaches for stability improvement and assessment, and provide recommendations for improving the stability of IPSCs. Inverted perovskite solar cells are promising for real-world energy harvesting, but suffer from issues with environmental stability. This Review discusses current understanding of stability in these devices and recent attempts to improve stability, as well as future directions that might enable their market roll-out.