Abstract
A novel swivel-cruciform 3,3′-bithiophene based hole-transporting material (HTM) with a low lying highest occupied molecular orbital (HOMO) level was synthesized. This new HTM (KTM3) in CH
3
NH
3
PbI
3
perovskite solar cells showed a higher
V
oc
(1.08 V) and fill factor (78.3%) compared to solar cells fabricated using the widely used spiro-OMeTAD.