Effect of [6,6]-Phenyl-C<inf>61</inf> butyric acid methyl ester (PCBM) agglomerated nanostructure on device performance in organic thin-film transistors

Abstract

The influence of [6,6]-phenyl C 61 -butyric acid methyl ester (PCBM) agglomerated nanostructure on device performance of pentacene-based organic thin-film transistors (OTFTs) were reported. The presence of PCBM layers on a SiO 2 gate dielectric resulted in a good electrical characteristics of pentacene-based OTFTs, including a relatively high mobility ( = 0.95-2.2 cm 2 V -1 s -1 ), low threshold voltages (V th = -1.1--5.4 V), a high on/off current ratio (I on /I off = 10 4 ), and a high value of subthreshold slope (SS = 6.5 V/decade). The surface topography studies reveal that the PCBM nanostructure could favor the reduction of grain boundaries, which resulted in a better transistor performance of pentacene-based OTFTs. The influence of PCBM on the molecular microstructure of pentacene thin films elucidates a reasonable explanation for higher performance on OTFTs.