Modification of Indium Tin Oxide Electrodes by Fluorinated Silanes for Transparent Organic Thin-Film Transistors

Transparent organic thin-film transistors (OTFTs) are promising for bioelectronics applications, by allowing simultaneous optical imaging with electrical sensing and modulation. However, the state-of-the-art transparent OTFTs have limited device performance, in terms of low mobility and high threshold voltage. This is mainly attributed to the large contact resistance induced by the energy level mismatch between the transparent electrodes and organic semiconductors. He re, we report transparent OTFTs with indium tin oxide electrodes modified by fluorinated silanes to improve device performance. It is found that the OTFTs with electrode modified by fluorinated silanes exhibit increased mobility from 0.12 cm2/<inline-formula> <tex-math notation="LaTeX">$\text{V}\cdot \text{s}$ </tex-math></inline-formula> to 1.58 cm2/<inline-formula> <tex-math notation="LaTeX">$\text{V}\cdot \text{s}$ </tex-math></inline-formula> and lower threshold voltage from–12.45 V to–2.21 V. The contact resistance of the OTFT characterized by a transmission line method, shows a reduction from over 1 <inline-formula> <tex-math notation="LaTeX">$\text{M}\Omega $ </tex-math></inline-formula> to below 100 <inline-formula> <tex-math notation="LaTeX">$\text{k}\Omega $ </tex-math></inline-formula>.