Modified P3HT materials as hole transport layers for flexible perovskite solar cells

Flexible perovskite solar cells (f-PSCs) are light-weight, conformal and thus ideal for seamless integration of photovoltaics onto wearable portable electronics. Nevertheless, the spread f-PSCs is limited by both lower efficiency compared to rigid counterparts employment costly materials. Among them, hole-transporting materials (HTM) represent most expensive component also a weak spot long-term stability, due poor resistance against heat moisture. Here, we propose poly-3-hexylthiophene (P3HT)-modified HTMs embodying benzothiadiazole (BTD) moieties as electron-poor host. BTD inserted along P3HT backbone, creating donor-acceptor system able promote charge mobility throughout HTM. A first series copolymers, synthetized Stille coupling, shows decrease benzothiadiazole/thiophene ratio (1:2, 1:4, 1:6), allowing modulate electronic optical properties. Additionally, greener approach (Kumada polycondensation) employed synthetize homologous copolymer (VI-LM-027) amount that, used HTM in f-PSCs, leads power conversion comparable commercially available improved stability under continuous illumination. Finally, VI-LM-027 6 × cm2 modules, delivering 6.9% on 16 active area demonstrating feasibility proposed large manufacture.