Zinc Porphyrin–Ethynylaniline Conjugates as Novel Hole-Transporting Materials for Perovskite Solar Cells with Power Conversion Efficiency of 16.6%

New zinc porphyrins Y2 and Y2A2 have been utilized in perovskite solar cells specifically as hole-transporting materials (HTMs) rather than photosensitizers. The combination of MAPbI 3 as photosensitizer and porphyrins as HTMs is a potential alternative to well-known MAPbI 3 /Spiro-OMeTAD hybrids owing to high performance and versatility toward molecular engineering of porphyrin families. A high efficiency of 16.60% is achieved by n -butyl tethered Y2 HTM ( V OC = 0.99 V; J SC = 22.82 mA cm –2 ) which is comparable to that of Spiro-OMeTAD of 18.03% ( V OC = 1.06 V; J SC = 22.79 mA cm –2 ). Both materials possess similar highest occupied molecular orbital level and the same order of magnitude of hole mobility at 10 –4 cm 2 V –1 s –1 . The slightly poorer performance of 10.55% ( V OC = 1.01 V; J SC = 17.80 mA cm –2 ) is obtained for n -dodecyl tethered Y2A2 HTM. This is believed to stem from more surface pinholes when deposited on perovskite leading to an order of magnitude slower mobility.