The Study of Organic Thin Film Transistor with Polymethylmethacrylate as a Dielectric Layer

The properties of pentacene-based organic thin film transistors (OTFTs) with polymethylmethacrylate (PMMA) as a dielectric layer have been investigated. The concentration of PMMA was about 8 wt % with toluene as solvent. The pentacene film on PMMA dielectric layer displays high thin-film quality according to results of x-ray diffraction scan and atomic force microscopy. The crystalline size was about 33.96 nm and the grain size was about 1000~1500 nm. The pentacene-based OTFTs with PMMA as a dielectric layer exhibited excellent electric characteristics, including high mobility of 0.241 cm2/V-s or larger, on/off current ratio of 104 or larger, and the threshold voltage of less than-6.3