A New Generation Co‐Assembled Small Molecular Gel with Polyaniline: Exciting Mechanical, Electronic and Photovoltaic Properties

Summary Folic acid (F), Fmoc‐protected phenylalanine (FP) and 5,5′‐(1,3,5,7‐tetraoxopyrrolo[3,4‐f]isoindole‐2,6‐diyl) diisophthalic acid (PMDIG) are used to produce co‐assembled gels with polyaniline(PANI). The formation of PANI inside the gel matrices are confirmed by FTIR and UV‐vis spectroscopy. UV‐vis spectra also exhibit the polaron band transitions of the doped PANI. Both F‐PANI and PMDIG‐PANI gels exhibit fibrillar network morphogy but the branching is more in the F‐PANI gel. The FP‐PANI gel however exhibits nanotubular morphology. The dc conductivity values of F‐PANI, FP‐PANI and PMDIG‐PANI xerogels are 0.14 × 10 −4 , 0.12 × 10 −1 and 0.3 × 10 −4  S/cm, respectively. The current–voltage ( I – V ) curves of the F‐PANI gel shows a negative differential resistance(NDR) property both at forward and backward bias. The I – V property of the FP‐PANI xerogel resembles to the behavior of a semiconductor‐metal junction and that of PMDIG‐PANI xerogel exhibits a signature of rectification property. A dye‐sensitized solar cell is also fabricated using the PMDIG‐PANI gel with a power conversion efficiency of 0.1%.