Low-Temperature-Deposited SiO2 Gate Insulator With Hydrophobic Methyl Groups for Bottom-Contact Organic Thin-Film Transistors

This study used a simple deposition method to fabricate hydrophobic SiO2 as an organic thin-film transistor (OTFT) gate insulator. The SiO2 gate insulator, which was deposited at 80 degrees C by plasma chemical vapor deposition using a tetraethoxysilane (TEOS) precursor gas, contained hydrophobic methyl (CH3) functional groups due to incompletely dissociated TEOS molecules. These CH3 functional groups made the SiO2 surface more hydrophobic and, thus, facilitated crystalline growth of the pentacene film, resulting in device performance that could be comparable to OTFTs with SiO2-based gate insulators deposited at higher temperatures. Therefore, we believe that the proposed 80 degrees C SiO2 gate insulator, which delivers a good performance, will enable the potential application of OTFTs on flexible substrates.