Pentacene-Based Thin-Film Transistors With a Solution-Process Hafnium Oxide Insulator

Abstract

<para xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> Pentacene-based organic thin-film transistors with solution-process hafnium oxide <formula formulatype="inline"><tex Notation="TeX">$(\hbox{HfO}_{x})$</tex></formula> as gate insulating layer have been demonstrated. The solution-process <formula formulatype="inline"><tex Notation="TeX">$\hbox{HfO}_{x}$</tex></formula> could not only exhibit a high-permittivity <formula formulatype="inline"><tex Notation="TeX">$(\kappa = \hbox{11})$</tex></formula> dielectric constant but also has good dielectric strength. Moreover, the root-mean-square surface roughness and surface energy <formula formulatype="inline"><tex Notation="TeX">$(\gamma_{s})$</tex></formula> on the surface of the <formula formulatype="inline"><tex Notation="TeX">$\hbox{HfO}_{x}$</tex></formula> layer were 1.304 nm and 34.24 <formula formulatype="inline"><tex Notation="TeX">$\hbox{mJ}/\hbox{cm}^{2}$</tex></formula>, respectively. The smooth, as well as hydrophobic, surface of <formula formulatype="inline"><tex Notation="TeX">$\hbox{HfO}_{x}$</tex></formula> could facilitate the direct deposition of the pentacene film without an additional polymer treatment layer, leading to a high field-effect mobility of 3.8 <formula formulatype="inline"><tex Notation="TeX">$\hbox{cm}^{2}/(\hbox{V} \cdot \hbox{s})$</tex> </formula>. </para>