P‐12: Enhanced Pentacene OTFTs with Suspended Source/Drain Electrode

We have proposed and fabricated a new triisopropylsilyl (TIPS) pentacene organic thin-film transistor (OTFT) by employing suspended source/drain (SSD) electrode which successfully improves the electrical properties such as field-effect mobility, on/off ratio, threshold voltage (VTH) and subthreshold slope compared to conventional bottom-contact OTFTs. The SSD electrode was fabricated by using Cr/Au double layer where the Cr was used as a sacrificial layer. By completely etching the Cr layer in the active area, a suspended Au source/drain structure is constructed forming a top-contact-like geometry. The field-effect mobility of ink-jet printed TIPS pentacene OTFT increased from 0.007 cm2/Vs to 0.066 cm2/Vs, on/off ratio increased from 104 to 106, VTH decreased from +9 V to −3 V and subthreshold slope decreased from 4.5 V/decade to 0.9 V/decade.