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Showing 1 to 20 of 57 for “"Pentacene"”.
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Pentacene Based Organic Electronic Devices
This thesis describes a study of pentacene-based organic electronic devices with poly(methyl methacrylate) (PMMA) and cross-linked PMMA (cPMMA) gate dielectrics. The electrical characteristics of pentacene-based organic thin-film transistors (OTFTs) using PMMA as the gate dielectric are reported. …
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Morphology and performance in pentacene
Thesis (M.Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1999.
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Chemoselective Oxidation of 6,13-Bis(decylthio) Pentacene
… because of their possible low cost production, Pentacene and pentacene derivatives are promising candidates for organic semiconductor research since their ^-conjugated electronic structures possess small HOMO- LUMO gaps and high field effect mobility. Whereas there is much potential in devices …
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Pentacene integrated thin-film transistors and circuits
… (< 95°C) process flow to fabricate pentacene integrated organic thin-film transistors (OTFTs) compatible with plastic substrates such as polyethylene terephthalate (PET). Integration of inkjet printed organic photoconductors (OPDs) based on titanyl pthalocyanine with OTFTs is …
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Threshold voltage in pentacene field effect transistors with parylene dielectric
… parylene is studied as a gate dielectric for pentacene OFETs. The three main areas of study were: (1) parylene's performance as a dielectric, (2) possible improvement of OFETs by surface treatments, and (3) the effects of interface traps on threshold voltage and parasitic bulk conductivity. …
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The bias-stress effect in pentacene organic thin-film transistors
… characteristics of the BSE in integrated pentacene OTFTs with polymer gate dielectric and encapsulation. Pentacene is used as the model organic semiconductor because it is the most widely used organic semiconductor for OTFTs. The measurements reveal that the BSE results from carriers that …
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Coherence and Singlet Fission of TIPS-Pentacene Probed by Two-dimensional Electronic Spectroscopy
… investigate 6,13-bis(triisopropylsilylethynyl)- pentacene (TIPS-Pn) in dilute solutions and nanoparticles (NPs) of two morphologies. In concentrated solutions and solids, TIPS-Pn undergoes singlet fission (SF), an exciton multiplicative process that has the potential to increase the efficiency of …
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Development of Nickel and Zirconium Mediated Cycloadditions for the Synthesis of Substituted Pentacene
… pathway for the synthesis of substituted pentacene. Preliminary efforts for the direct polymerization of poly[n]acene are herein described including the investigation of a possible [4+2] cycloaddition of zirconium-benzyne and 1,3-diynes.
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Integration of pentacene-based thin film transistors via photolithography for low and high voltage applications
An organic thin film transistor (OTFT) technology platform has been developed for flexible integrated circuits applications. OTFT performance is tuned by engineering the dielectric constant of the gate insulator and the insulator/semiconductor interface. Full integration is enabled by a low …
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Ultrafast Charge and Energy transfer Dynamics in Organic-Transition Metal Dichalcogenides Heterostructures
… physics of Organic-TMD Heterostructures, namely Pentacene/MoTe2 and Pentacene/WSe2 were examined. It was found that excitation at the electronic gap of MoTe2 leads to a Type II to type I band alignment cross over in Pentacene/MoTe2 heterostructure, due to a mechanism known as carrier-driven …
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Polarization-induced transport in ferroelelctric organic field-effect transistors
… small molecule organic semiconductors -- pentacene and 6,13 bis(triisopropylsilylethynyl)pentacene (TIPS-pentacene) -- along with a copolymer PVDF-TrFE as the dielectric layer, the FET characteristics are monitored as a function of temperature. Pentacene FETs show a weak temperature …
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INTERFACE EFFECTS ON NANOELECTRONICS
… structures is extremely important. I fabricated pentacene thin film transistors on Si/SiO<sub>2</sub> and varied the conduction channel thickness from effectively bulk (~40nm) to 2 continuous conducting layers to examine the effect of substrate on noise generation. The electronic spectral noise …
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Singlet exciton fission, a multi-exciton generation process, in organic semiconductor solar cells
… using the singlet fission material pentacene as donor and low bandgap infrared-absorptive lead chalcogenide quantum dots as acceptors. Singlet fission can enhance the efficiency of organic photovoltaics only if the fission material is paired with an absorptive low-energy-gap …
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Electronic Structure Modelling of Singlet Fission in Organic Photovoltaics
… crystals and dimers, using the well-studied pentacene molecule as a reference system. Linear-scaling density functional theory (LS-DFT) is used to model the influence of the crystal environment on charge-transfer (CT) configurations in the pentacene molecular crystal. We derive a general …
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Singlet Exciton Fission in Acene Dimer and Diradicaloid Molecules
… different acene dimers and diradicaloids. In pentacene and tetracene dimers, we investigate their mechanism of singlet fission. In a series of diradicaloids, we study the relation between molecular structure, diradical character and the suitability for singlet fission. In the first two …
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DIRECT REAL-TIME REAL-SPACE IMAGING OF ENERGY TRANSPORT IN ORGANIC SEMI-CONDUCTORS
… formed between a perylene diimide (PDI) and pentacene. Through femtosecond transient absorption microscopy (with sub-10 fs temporal and sub-10 nm spatial precision), supplemented by various other experiments and modelling, we show that ultrafast energy transport in the PIC systems can be …
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SYNTHESIS OF CONJUGATED SMALL MOLECULES AND POLYMERS BY A PALLADIUM CATALYZED CYCLOPENTANNULATION STRATEGY – TOWARDS NEW ORGANIC SEMICONDUCTORS
… used to synthesize a new class of stabilized pentacene derivatives with externally fused five-membered rings. The target compounds were synthesized via chemical manipulation of a partially saturated 6,13-dibromopentacene precursor that can be fully aromatized in a final step via a DDQ mediated …
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Organic solar cells based on liquid crystalline and polycrystalline thin films
… improvements.In an alternative approach, p-type pentacene thin films prepared by physical vapor deposition were incorporated into heterojunction solar cells with C60 as n-type layers. Power conversion efficiencies of 2.7 % under broadband illumination (350-900 nm) with a peak external quantum …
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Spin and Charge Dynamics in Organic Semiconductors
… gained. Spin lifetime investigations in TIPS-pentacene and diF-TES-ADT are presented in chapter 7 and appendix A with chapter 4 detailing electron spin resonance and its use in spin lifetime studies. We present the full fabrication procedure to obtain ESR devices and ESR measure ments on …
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Ultrafast Spectroscopy of Organic Semiconductors: Singlet Fission and Nonfullerene Acceptors for Organic Photovoltaics
… us to examine singlet fission in films of pentacene, fluorinated pentacene, and coevaporated blends of various mixing ratios. We directly observe an intermolecular charge transfer state during singlet fission in solid films of coevaporated pentacene and peruoropentacene, which supports the …
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