Modulating the Surface via Polymer Brush for High‐Performance Inkjet‐Printed Organic Thin‐Film Transistors. (19th December 2016)

• Record Type: Journal Article
• Authors: Ge, Feng; Wang, Xiaohong; Zhang, Yunfeng; Song, Eunjoo; Zhang, Guobing; Lu, Hongbo; Cho, Kilwon; Qiu, Longzhen
• Is Part Of: Advanced Electronic Materials. Volume 3:Number 1(2017)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2016-12-19
• Subjects: inkjet printing -- organic field‐effect transistors -- structure–property relationships -- surface modification; Materials -- Electric properties -- Periodicals; Materials science -- Periodicals; Magnetic materials -- Periodicals; Electronic apparatus and appliances -- Periodicals; 537
• DOI: 10.1002/aelm.201600402
• Languages: English
• ISSNs: 2199-160X

Abstract

Abstract : A strategy is reported to control the morphologies of inkjet‐printed small organic molecule semiconductor by modifying printed surfaces with polymer brushes. Polystyrene (PS) brushes with different chain lengths from 1.66 to 7.35 nm are grafted onto a dielectric surface via surface‐initiated atom transfer radical polymerization to form uniform, hydrophobic surfaces. Single droplets of 6, 13‐bis(triisopropylsilylethynyl) pentacene (TIPS‐pentacene) are then inkjet‐printed onto these PS brush‐modified substrates. TIPS‐pentacene crystals are obtained with different morphologies depending on the chain length of the PS brushes. Short PS chains behave like self‐assembled monolayers on the dielectric surface such that small crystals are formed with random orientations. Longer PS chains become partially extended in the solvent altering ink spreading, contact‐line pinning, solute migration, and ultimately crystallization. Large self‐assembled crystals are generated with highly oriented structures. Organic thin film transistors are fabricated by printing single dots of TIPS‐pentacene. The device based on PS brushes of 5.14 nm exhibits the optimal device performances with an average mobility of 0.35 ± 0.23 cm 2 V −1 s −1 . These results demonstrate that these polymer brushes provide a route toward further understanding inkjet‐printing techniques for high‐performance organic electronics. Abstract : Polystyrene (PS) brushes with different chain lengths from 1.66 to 7.35 nm are used to modify the surface layers during inkjet printing of thin‐film transistors. Inkjet‐printed single droplets of 6, 13‐bis(triisopropylsilylethynyl) pentacene on PS brush‐modified substrates are obtained with different morphologies. The device based on PS brushes of 5.14 nm exhibits an optimal average mobility of 0.35 ± 0.23 cm 2 V −1 s −1 .