Fig. 2. (a) Double logarithmic J–V curves measured under dark of hole only device based on pristine Spiro-OMeTAD (coded as Spiro), LiTFSI and TBP doped Spiro-OMeTAD (coded as Spiro/Li/TBP) as well as LiTFSI, TBP and FeCl3 doped Spiro-OMeTAD (code as Spiro/Li/TBP/FeCl3). (b) Hole mobility of Spiro-OMeTAD with or without dopants. The thickness of the HTM films is kept the same (80 nm).
