In-situ fast oxidation of spiro-OMeTAD hole transport layers under ambient indoor lighting compatible with air-processed perovskite solar cells

Doped spiro-OMeTAD with lithium salt and 4-tert-butylpyridine is widely employed in perovskite solar cells. Under low-intensity indoor light, photogenerated hole transfer from the perovskite to the hole transport layer drives rapid oxidation of the doped spiro-OMeTAD, reducing the reaction time by over tenfold compared to dark conditions.