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Solution processible poly(4-vinylphenol) is employed as a transistor dielectric material for low cost processing on flexible substrates at low temperatures. A 6,13-bis (triisopropylsilylethynyl) (TIPS) pentacene–graphene hybrid semiconductor is drop cast to fabricate bottom-gate and bottom-contact field-effect transistor devices on flexible and glass substrates under an ambient air environment. A few layers of graphene flakes increase the area in the conduction channel, and form bridge connections between the crystalline regions of the semiconductor layer which can change the surface morphology of TIPS pentacene films. The TIPS pentacene–graphene hybrid semiconductor-based organic thin film transistors (OTFTs) cross-linked with a poly(4-vinylphenol) gate dielectric exhibit an effective field-effect mobility of 0.076 cm2 V−1 s−1 and a threshold voltage of −0.7 V at Vgs = −40 V. By contrast, typical TIPS pentacene shows four times lower mobility of 0.019 cm2 V−1 s−1 and a threshold voltage of 5 V. The graphene/TIPS pentacene hybrids presented in this paper can enhance the electrical characteristics of OTFTs due to their high crystallinity, uniform large-grain distribution, and effective reduction of crystal misorientation of the organic semiconductor layer, as confirmed by x-ray diffraction spectroscopy, atomic force microscopy, and optical microscopy studies. [ABSTRACT FROM AUTHOR]

High-performance pentacene-based thin-film transistors and inverters with solution-processed barium titanate (BTO) insulators are demonstrated. The current–voltage characteristics of the transistors show high mobility of 9.53 \cm^2\V^-1\s^-1 at smaller VG = -\3.5\ \V and VD = -\5\ \V, a low threshold voltage of -1.5 V, and a subthreshold slope of 599 mV/dec. Large grain and small crystalline sizes are observed from atomic force microscopy images and X-ray diffraction analysis of pentacene films. The results are verified through Raman spectroscopy and a theoretical Marcus–Hush equation to understand the higher intermolecular coupling, resulting in easier carrier transports in pentacene molecules. In order to investigate the behavior of high-permittivity materials of BTO insulators in a logic circuit, simple and low-operating-voltage inverters are fabricated, and the gain is approximately 8.76 under a small operating voltage range from 0 to -5 V. [ABSTRACT FROM PUBLISHER]

Pentacene-based organic thin-film transistors with solution-processed barium zirconate titanate dielectric layers are demonstrated. According to the programming/erasing operations, the devices exhibited memory characteristics, such as reversible threshold voltage shifts and nondestructive readout. In addition, the reliability of the memory devices was confirmed by data retention time and repeated switching cycles' endurance testing. In addition, the possible mechanism of the memory effect was also discussed. These results suggest that the devices could potentially be applied to nonvolatile memory applications in organic electronics. [ABSTRACT FROM AUTHOR]

Pentacene-based organic thin-film transistors (OTFTs) with solution-processed barium titanate (\Ba1.2\Ti0.8\O3) as a gate insulator are demonstrated. The electrical properties of pentacene-based TFTs show a high field-effect mobility of 8.85 \cm^2 \cdot \V^-1 \cdot \s^-1, a low threshold voltage of -1.89 V, and a low subthreshold slope swing of 310 mV/decade. The chemical composition and binding energy of solution-processed barium titanate thin films are analyzed through X-ray photoelectron spectroscopy. The matching surface energy on the surface of the barium titanate thin film is 43.12 \mJ \cdot \m^-2, which leads to Stranski–Krastanov mode growth, and thus, high mobility is exhibited in pentacene-based TFTs. [ABSTRACT FROM AUTHOR]

Pentacene-based organic thin-film transistors with solution-process hafnium oxide (HfO∞) as gate insulating layer have been demonstrated. The solution-process HfO∞ could not only exhibit a high-permittivity (K = 11) dielectric constant but also has good dielectric strength. Moreover, the root-mean-square surface roughness and surface energy (γS) on the surface of the HfO∞ layer were 1.304 nm and 34.24 mJ/cm2, respectively. The smooth, as well as hydrophobic, surface of HfO∞ 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 cm2/(V ∙ s). [ABSTRACT FROM AUTHOR]