Stabilizing doped Spiro-OMeTAD by organic molten salt for efficient and stable perovskite solar cells

Bis(trifluoromethane)sulfonimide (LiTFSI) and 4-tert-butylpyridine (TBP) have been currently suggested to be irreplaceable in classic doped 2,2′,7,7′-tetrakis (N,N-di-p-methoxyphenylamine)-9,9′-spirobifluorene (Spiro-OMeTAD) for high-performance perovskite solar cells (PSCs). However, the stability of Spiro-OMeTAD was...