Self-healing and efficient flexible perovskite solar cells enabled by host-guest interaction and a 2D/3D heterostructure

Flexible perovskite solar cells (F-PSCs) have attracted enormous attention in portable and wearable electronics due to their low-cost and high power-per-weight. However, there is still much room for development with respect to the moisture and mechanical stability of F-PSCs, which prevents their final commercialization. Herein, we report a new self-healing, high-efficiency F-PSC that incorporates a host-guest in situ synthesized ter-polymer as a self-healing unit and a 2D/3D heterostructure perovskite as a moisture shielding and passivation layer. Consequently, the strategy not only offers decent efficiencies of 23.06% on rigid substrates and over 20% on flexible substrates, but also improves the mechanical stability of F-PSCs, that is, similar to 90% of the original efficiency could be recovered after self-healing during 4000 bending cycles. This solution addresses the stability concern of F-PSCs and other applications and represents an important step for large-scale production.