Soluble N-Type organic thin-film transistors with enhanced electrical characteristics

We fabricated and investigated soluble, organic, thin-film transistors (OTFTs) containing ‘[6, 6]-phenyl-C61-butyric acid methyl ester (PCBM)’ as a semiconducting layer, and an organic dielectric buffer (cross-linked poly-4-vinylphenol) as a dielectric buffer-layer to improve electrical characteristics. The semiconducting layer of the devices was fabricated by the drop-casting method where PCBM was dissolved in three different solvents (odichlorobenzene, chloroform, and chlorobenzene). From the transfer and output characteristics of the PCBM OTFTs, a threshold voltage of 10 V, sub-threshold slope of 10 V/dec, on/off current ratio of 7.305 × 103, and field-effect mobility of 1.53 × 10−2 cm2/Vs were obtained; for PCBM using o-dichlorobenzene solvent and an organic dielectric buffer layer. It was also found that the hysteresis for the same device was improved conspicuously compared to the other devices, by the above-mentioned condition.