Pentacene

About: Pentacene is a research topic. Over the lifetime, 5051 publications have been published within this topic receiving 161481 citations. The topic is also known as: 2,3:6,7-dibenzanthracene & benzo[b]naphthacene.

Tuning of Ag work functions by self-assembled monolayers of aromatic thiols for an efficient hole injection for solution processed triisopropylsilylethynyl pentacene organic thin film transistors

Abstract: We demonstrate tuning of hole injection barriers in bottom contact triisopropylsilylethynyl pentacene (TIPS-pentacene) organic thin film transistors (OTFTs) by forming the self-assembled monolayers (SAMs) of thiophenol, 4-fluorothiophenol, or pentafluorothiophenol on the pristine Ag electrode. The work functions of SAM-treated Ag electrodes are measured by Kelvin probe method. The TIPS-pentacene OTFT devices were fabricated by a drop-cast method with a micropipette like an inkjet printing. The OTFTs with pentafluorothiophenol-Ag electrodes as source and drain exhibit carrier mobility of 0.17cm2∕Vs and on/off current ratio of 105 because of almost no hole injection barrier to TIPS pentacenes. The SAM-treated Ag electrodes are robust over repeated electrical scans of 100cycles.

Nuclear tunneling effects of charge transport in rubrene, tetracene, and pentacene

Abstract: The mechanism of charge transport in organic materials is still controversial from both experimental and theoretical perspectives. At room temperature, molecular deformations interact strongly with the charge carrier both through intermolecular and intramolecular phonons, suggesting a thermally activated hopping mechanism as described by the Marcus electron transfer theory. However, several experimental measurements have indicated that the electronic transport behaves in a ``bandlike'' manner, as indicated by a decrease in mobility with increasing temperature, in contradiction to the Marcus description. Bandlike first-principles calculations based on the Holstein-Peierls model tend to overestimate the charge mobility by about 2 orders of magnitude. Here, a hopping model is derived that not only quantitatively describes the charge mobility but also explains the observed bandlike behavior. This model uses the quantum version of charge-transfer theory coupled with a random-walk simulation of charge diffusion. The results bridge the gap between the two extreme mechanisms. This first-principles method predicts the room-temperature hole mobilities to be 2.4, 2.0, and $0.67\text{ }{\text{cm}}^{2}/\text{V}\text{ }\text{s}$, for rubrene, pentacene, and tetracene, respectively, in good agreement with experiment.

Anisotropic field effect mobility in single crystal pentacene

Abstract: Fan-shaped electrodes were designed on Si∕SiO2 substrate to measure the anisotropic field effect mobility in freestanding single crystal pentacene. Field effect transistor was fabricated by placing single crystal pentacene on the prepatterned electrodes. The contact between the electrodes and single crystal pentacene was enhanced by applying pressure. Angle dependence of field effect mobility in single crystal pentacene showed remarkably anisotropic behavior. The highest mobility value was estimated to be ∼2.3cm2∕Vs at room temperature.

Improved organic thin-film transistor performance using novel self-assembled monolayers

Abstract: Pentacene-based organic thin-film transistors have been fabricated using a phosphonate-linked anthracene self-assembled monolayer as a buffer between the silicon dioxide gate dielectric and the active pentacene channel region. Vast improvements in the subthreshold slope and threshold voltage are observed compared to control devices fabricated without the buffer. Both observations are consistent with a greatly reduced density of charge trapping states at the semiconductor-dielectric interface effected by introduction of the self-assembled monolayer.

Morphology and electronic transport of polycrystalline pentacene thin-film transistors

Abstract: Temperature-dependent measurements of thin-film transistors were performed to gain insight in the electronic transport of polycrystalline pentacene. Devices were fabricated with plasma-enhanced chemical vapor deposited silicon nitride gate dielectrics. The influence of the dielectric roughness and the deposition temperature of the thermally evaporated pentacene films were studied. Although films on rougher gate dielectrics and films prepared at low deposition temperatures exhibit similar grain size, the electronic properties are different. Increasing the dielectric roughness reduces the free carrier mobility, while low substrate temperature leads to more and deeper hole traps.