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.

Anthradithiophene-Containing Copolymers for Thin-Film Transistors and Photovoltaic Cells

Abstract: We synthesized anthradithiophene−cyclopentadithiophene conjugated copolymers via Stille coupling. The anthradithiophene core was verified to be superior in stability compared to pentacene toward Diels−Alder cycloaddition and therefore more compatible with fullerenes, acceptor material commonly used in bulk heterojunction (BHJ) photovoltaic cells. The polymers exhibit high film absorption coefficients of 105 cm−1, an order of magnitude higher than previously reported anthradithiophene−dialkylfluorene copolymers. Short-circuit currents exceeding 5 mA/cm2 and a BHJ device efficiency close to 1% were achieved when device morphology was improved with diiodooctane as a solvent additive. This is the highest power conversion efficiency achieved by an acene-containing polymer so far.

Flexible semitransparent pentacene thin-film transistors with polymer dielectric layers and NiOx electrodes

Abstract: We have fabricated the flexible semitransparent pentacene-based thin-film transistors (TFTs) with poly-4-vinylphenol (PVP) dielectric layers which were deposited by spin coating on a thermostable plastic substrate with a conductive film. For the source∕drain (S∕D) electrodes of our flexible pentacene TFTs both Au and semitransparent NiOx have been tested. It was found that NiOx was better matched to the pentacene channel for the S∕D contacts than Au. Our flexible pentacene TFTs with semitransparent NiOx contacts exhibited mobility of ∼0.24cm2∕Vs higher than that achieved with Au contacts (∼0.14cm2∕Vs) and also demonstrated a higher initial drain current.

Low Subthreshold Swing HfLaO/Pentacene Organic Thin-Film Transistors

Abstract: We have integrated a high-kappa HfLaO dielectric into pentacene-based organic thin-film transistors. We measured good device performance, such as a low subthreshold swing of 0.078 V/dec, a threshold voltage of -1.3 V, and a field-effect mobility of 0.71cm2/ Vldrs . This occurred along with an ON-OFF state drive current ratio of 1.0 times 105, when the devices were operated at only 2 V. The performance is due to the high gate-capacitance density of 950 nF/cm2 that is given by the HfLaO dielectric, which is achieved at an equivalent oxide thickness of only 3.6 nm with a low leakage current of 5.1 times 10-7 at 2 V.

Layer-by-layer growth of incommensurate, polycrystalline, lying-down pentacene thin films on Au(111)

Abstract: Pentacene, as well as other polyacenes, is known to adsorb on metal surfaces in a lying-down geometry, that is, with the molecular plane parallel to the surface. Here we show using scanning tunneling microscopy that the lying-down pentacene monolayer seeds the growth of a multilayer polycrystalline film in a layer-by-layer fashion, with the molecular planes parallel to the substrate surface. Growth in the submonolayer region is characterized by a large number of ordered molecular structures as coverage increases. The saturated monolayer structure remains approximately the same throughout multilayer coverages studied. Statistical analysis of molecular domain orientation reveals that the ordered pentacene structures are incommensurate with the Au(111) substrate and growth beyond the monolayer region is a mixture of epitaxy and nonepitaxy. We conclude that the relatively large footprint of a lying-down pentacene molecule smoothes out lateral corrugation in the adsorption energy landscape on the Au(111) surfa...

Improvement of Metal–Insulator–Semiconductor-Type Organic Light-Emitting Transistors

Abstract: We developed metal–insulator–semiconductor-type organic light-emitting transistors (MIS-OLETs), and improved their properties by optimizing the device structure. MIS-OLETs showed a maximum drain current of ID = -149 µA, maximum luminance of 1034 cd/m2 (VD = -20 V, VG = -50 V) and on/off ratio of over 104. Moreover an active-matrix display using MIS-OLETs on a plastic substrate was fabricated. The developed 16×16 active-matrix-drive organic light-emitting transistors (AMOLET) showed excellent properties by optimizing device structure.