Low-Bandgap Organic Bulk-Heterojunction Enabled Efficient and Flexible Perovskite Solar Cells

Lead halide perovskite and organic solar cells (PSCs and OSCs) are considered as the prime candidates currently for clean energy applications due to their solution and low-temperature processibility. Nevertheless, the substantial photon loss in near-infrared (NIR) region and relatively large photovoltage deficit need to be improved to enable their uses in high-performance solar cells. To mitigate these disadvantages, low-bandgap organic bulk-heterojunction (BHJ) layer into inverted PSCs to construct facile hybrid solar cells (HSCs) is integrated. By optimizing the BHJ components, an excellent power conversion efficiency (PCE) of 23.80%, with a decent open-circuit voltage (V-oc) of 1.146 V and extended photoresponse over 950 nm for rigid HSCs is achieved. The resultant devices also exhibit superior long-term (over 1000 h) ambient- and photostability compared to those from single-component PSCs and OSCs. More importantly, a champion PCE of 21.73% and excellent mechanical durability can also be achieved in flexible HSCs, which is the highest efficiency reported for flexible solar cells to date. Taking advantage of these impressive device performances, flexible HSCs into a power source for wearable sensors to demonstrate real-time temperature monitoring are successfully integrated.

Automated summary

Lead halide perovskite and organic solar cells are seen as promising candidates for clean energy applications, but improvements are needed in the near-infrared photon loss and photovoltage deficit. By integrating low-bandgap organic bulk-heterojunction layers into inverted PSCs, high-performance hybrid solar cells can be constructed. These hybrid solar cells demonstrate excellent power conversion efficiency, extended photoresponse, and superior long-term stability compared to single-component PSCs and OSCs. With the highest efficiency reported for flexible solar cells to date, flexible HSCs can be integrated as a power source for wearable sensors, demonstrating real-time temperature monitoring capabilities.