Deposition of Pentacene Thin Film on Polydimethylsiloxane Elastic Dielectric Layer for Flexible Thin-Film Transistors

Abstract

A novel method was applied to realize the uniform and dense pentacene thin film on the elastic polydimethylsiloxane (PDMS) dielectric layer via vacuum deposition. The oxygen (O <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> ) plasma treatment followed by octadecyltrichlorosilane (OTS) vapor treatment was found to be important for the successful deposition of pentacene thin film with large grain size and hence high field-effect mobility. The highest mobility of the obtained pentacene-based organic thin-film transistors (OTFTs) was 0.65 cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> V <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-1</sup> s <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-1</sup> at the optimized condition with O <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> plasma treatment of 100 s and OTS treatment of 7 h. Furthermore, the flexible pentacene OTFTs based on PDMS dielectric layer were successfully fabricated. This letter opens up the capability of PDMS as dielectric layer for the fabrication of the vacuum-deposited devices, exhibiting a strong potential for future large-scale flexible and conformal electronics.