An efficient electron transport properties of fullerene functionalized with tricyanovinyldihydrofuran (TCF)

Abstract The charge mobility is an important property of organic optoelectronic materials. Fullerene (C60) derivatives have been extensively used as electron acceptor materials in optoelectronics. However, the effect of structural modification of fullerene with furan moieties on its charge transport characteristics has rarely been studies. Herein, we synthesized (E)-2-(3-cyano-5,5-dimethyl-4-styrylfuran-2(5H)-ylidene)malononitrile (S1), phenyl functionalized C60 (S2) and furan functionalized C60 (S3) using S2 as a reactant. These compounds have been fully characterized by means of FTIR, 1H NMR, 13C NMR spectroscopy and MALDI-TOF spectrometry for their structure. The photophysical and electrochemical characteristics of S1, S2 and S3 were studied to understand the effect of structural architecture change of C60over redox and optical properties. The electron mobility inS1, S2 and S3 was studied using space-charge limiting current (SCLC) model where, S3 shows 18x higher mobility than the most used acceptor PB61BM. After thermal treatment at 70°C, S1, S2 and S3 displayed a maximum electron mobility (μe) of (1.39 ± 0.30) × 10−3, (1.3 ± 0.24) × 10−4 and (1.84 ± 0.26) × 10−3 cm2/V.s respectively. Further, computational method was employed to model the S1, S2 and S3electronic structure and frontier electron transitions. Both HOMO and LUMO states drop by exactly the same amount upon structural change from S2 to S3 to give equal Eg when calculated using B3LYP. This suggests that conjoint molecular architecture of TCF and fullerene exhibits interesting photophysical and electrochemical an efficient charge transport properties.