Position effect of arylamine branches on pyrene-based dopant-free hole transport materials for efficient and stable perovskite solar cells

In this work, arylamine branches N-4-[4-[Bis(4-methoxyphenyl)-amino]phenyl]-N-1,N-1-bis(4-methoxyphenyl)-1,4-benzenediamine are introduced to the 1,6- and 2,7-positions of pyrene core to afford two novel HTMs coded PYR16 and PYR27. The influence of different positions of arylamine units on the optical and electronic properties and the performance of PSCs are investigated. The perovskite solar cells (PSCs) using dopant-free PYR16 exhibite a PCE of 17.00%, which is higher than that of PYR27 (14.67%). Furthermore, the PSCs based on PYR16 obtain better stability than those using PYR27 by maintaining 98% of the initial values after 1080 h at 80 degrees C in an ambient environment in the dark and 85% of initial values after 672 h under continuous sunlight soaking in an ambient environment at 45-50 degrees C.