Recent progress in flexible perovskite solar cells: Materials, mechanical tolerance and stability

Portable electronic devices with standalone power sources are increasingly demanded. Flexible photovoltaics devices for solar energy conversion remain the most attractive option to cater for this demand. Flexible solar cells have the advantages of light-weight, roll-to-roll processing, conformability, bendability and wearability. Following the excellent power conversion efficiencies (PCEs) of perovskite solar cells (PSCs) on rigid substrates, flexible perovskite solar cells (flex-PSCs) have gained remarkable research attentions. Successes have been recorded for flex-PSCs with conversion efficiency reaching 17.3%. Attainment of commercialization of flex-PSCs and integration into electronic gadgets require proper materials selections and processing techniques coupled with good resistance to deformation and long-term durability. This work reviews (i) comprehensively, materials and processing techniques used for the fabrication of flex-PSCs; (ii) mechanical tolerance of flex-PSCs and (iii) stability of flex-PSCs in different environmental conditions.