Flexible and stretchable organic solar cells (OSCs) have attracted enormous attention due to their potential applications in wearable and portable devices. To achieve flexibility and stretchability, many efforts have been made with regard to mechanically robust electrodes, interface layers, and photoactive semiconductors. This has greatly improved the performance of the devices. State‐of‐the‐art flexible and stretchable OSCs have achieved a power conversion efficiency of 15.21% (16.55% for tandem flexible devices) and 13%, respectively. Here, the recent progress of flexible and stretchable OSCs in terms of their components and processing methods are summarized and discussed. The future challenges and perspectives for flexible and stretchable OSCs are also presented.

Poly(ethylene glycol) diacrylate (PEGDA) is introduced into the SnO 2 dispersion as the polymer framework to hinder the agglomeration. The PEGDA-modified SnO 2 acted as the electron transport layer (ETL) in n-i-p structured perovskite solar cells (pero-SCs). It is demonstrated that the PEGDA plays multifunctional roles in the enhancement of photovoltaic performance and stability against illumination and humility. First, the PEGDA-modified SnO 2 ETL is more uniform, and its energy level matched well with the perovskite, which could facilitate the carrier transport and reduce the energy loss. Second, PEGDA could passivate the defects at the interface between perovskite and ETL. Eventually, a power conversion efficiency (PCE) of 23.31% is achieved for the α-FAPbI 3 based pero-SCs. Most importantly, the unencapsulated devices maintained more than 90% of the initial PCE after 850 h continuous illumination (100 mW/cm 2 ). This study could provide insight for the low-cost, facile, and efficient interface modification for the pero-SCs.

A "s-hole''-containing small molecule is used as an additive for organic solar cells 16.5% efficiency organic solar cells are achieved with additive engineering Excellent stability and easy processability are obtained with the additive