A tale of two organic small molecular hole transporting materials: Showing same extended shelf-life but very different efficiency of inverted MAPbI3 perovskite solar cells

This paper mainly discusses the structure-property relationship of two donor-acceptor-donor (D–?–A–?–D) type dopant-free hole transporting materials (HTMs) (TPA-TPy and TPA-Py-PTZ) comprising primarily 2,4,6-trisubstituted pyridine as acceptor core 4,4?-dimethoxytriphenylamine peripheral donor groups their use in p-i-n perovskite solar cells (PVSCs). Compared to inferior TPA-Py-PTZ, TPA-TPy has a superior extraction transport at HTM/perovskite interface. The pinhole-free, smooth dense, fully covered well-crystallized MAPbI3 layer on reduces carrier recombination substantially improves short circuit current density (JSC), open voltage (VOC), fill-factor (FF) PVSCs. PVSC employing HTM exhibits power conversion efficiency (PCE) 15.33% with JSC 23.69 mA cm?2, VOC 0.95 V, FF 68.10%. Especially, both TPA-Py-PTZ PVSCs exhibit better moisture stability than that NiOx It is because hydrophobic nature which enables formation having larger grain-size, less grain boundary, infiltration moisture.