Research On Small-molecule Organic Field-effect Transistors

Since the 1980 s, the organic field-effect transistors(OFETs) as a novel device have attracted increasing attention and have made great progress because they possess advantages of which inorganic field-effect transistors don’t have. For instance, its high flexible of modification, extensive selection of materials, easy fabrication, low cost and large area processing in electronic component. In recent years, realization of improving performance of OFET device is an important research subject,playing a significant role in realizing pure organic circuit in the future.This article focus on the research of enhancing performance of small-molecule based OFET. In this work, after introducing background, significance, application, issues in development history, structures, materials, working principle and characterization of OFET devices, fabrication process and measure methods are also described. Research contents of this paper are divided into three parts, including:1) Mo O3 and doped layer are used to modify the interface of electrode and organic semiconductor(OSC) and the interface between OSC and dielectric, respectively, to explore the relationshipbetween threshold voltage and doping ratio. Threshold voltage of the optimal device is-1 Vrather than-10.2 V of standard device.Its carrier mobility achieves 9×10-4 cm2/V?s. Afterannealing the fabricated device at 130 ℃ for 25 min, the threshold voltage of device is-2 Vand its carrier mobility achieves 1.9×10-3 cm2/V?s.2) Mo O3 is used as doping material to fabricated pentacene-based OFET device. Its thresholdvoltage is-2 V rather than-5.1 V of standard device and its carrier mobility achieves 1×10-2cm2/V?s. By adjusting the deposition rate of pentacene, threshold voltage of device isdecreased to-1.7 V and carrier mobility of device achieves 3×10-2 cm2/V?s.3) The OFET devices based on Cu Pc(copper phthalocyanine) and pentacene with Mo O3 anddoped layers are applied to DNA sensing and then experimental result is analyzed with furtherresearch program being proved.