Dithieno[3, 2‐b:2′, 3′‐d]pyrrole Cored p‐Type Semiconductors Enabling 20 % Efficiency Dopant‐Free Perovskite Solar Cells. (19th August 2019) - Zhou, Jie
Abstract: Organic p‐type semiconductors with tunable structures offer great opportunities for hybrid perovskite solar cells (PVSCs). We report herein two dithieno[3, 2‐b:2′, 3′‐d]pyrrole (DTP) cored molecular semiconductors prepared through π‐conjugation extension and an N‐alkylation strategy. The as‐prepared conjugated molecules exhibit a highest occupied molecular orbital (HOMO) level of −4.82 eV and a hole mobility up to 2.16×10 −4 cm 2 V −1 s −1 . Together with excellent film‐forming and over 99 % photoluminescence quenching efficiency on perovskite, the DTP based semiconductors work efficiently as hole‐transporting materials (HTMs) for n‐i‐p structured PVSCs. Their dopant‐free MA0.7 FA0.3 PbI2.85 Br0.15 devices exhibit a power conversion efficiency over 20 %, representing one of the highest values for un‐doped molecular HTMs based PVSCs. This work demonstrates the great potential of using a DTP core in designing efficient semiconductors for dopant‐free PVSCs. Abstract : Fein abgestimmt : Halbleiter vom p‐Typ mit einem Dithieno[3, 2‐b:2′, 3′‐d]pyrrol‐Kern wurden als dotierungsfreie Lochtransportmaterialien für Perowskit‐Solarzellen mit einer Effizienz von über 20 % entwickelt. Die Modifizierung über π‐Systemerweiterung und N‐Alkylierung führt zur Feinabstimmung von HOMO‐Energieniveaus, Lochmobilität, Löslichkeit und filmbildenden Charakteristika.