Journal ArticleDOI
Influence of Electric Field on Microstructures of Pentacene Thin‐Films in Field‐Effect Transistors
Horng Long Cheng,Wei Yang Chou,Chia Wei Kuo,Yu-Wu Wang,Yu Shen Mai,Fu Ching Tang,Shu Wei Chu +6 more
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TLDR
In this paper, the effect of electric field on the herringbone packing of pentacene molecules in a solid film is investigated, and it is shown that large electric fields may alter the molecular geometry and further induce structural phase transitions in the pentaene films.Abstract:
We report on electric-field-induced irreversible structural modifications in pentacene thin films after long-term operation of organic field-effect transistor (OFET) devices. Micro-Raman spectroscopy allows for the analysis of the microstructural modifications of pentacene in the small active channel of OFET during device operation. The results suggest that the herringbone packing of pentacene molecules in a solid film is affected by an external electric field, particularly the source-to-drain field that parallels the a-b lattice plane. The analysis of vibrational frequency and Davydov splitting in the Raman spectra reveals a singular behavior suggesting a reduced separation distance between pentacene molecules after long-term operations and, thus, large intermolecular interactions. These results provide evidence for improved OFET performance after long-term operation, related to the microstructures of organic semiconductors. It is known that the application of large electric fields alters the semiconductor properties of the material owing to the generation of defects and the trapping of charges. However, we first suggest that large electric fields may alter the molecular geometry and further induce structural phase transitions in the pentacene films. These results provide a basis for understanding the improved electronic properties in test devices after long-term operations, including enhanced field-effect mobility, improved on/off current ratio, sharp sub-threshold swing, and a slower decay rate in the output drain current. In addition, the effects of source-to-drain electric field, gate electric field, current and charge carriers, and thermal annealing on the pentacene films during OFET operations are discussed.read more
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Journal ArticleDOI
Experimental techniques for the fabrication and characterization of organic thin films for field-effect transistors.
Journal ArticleDOI
Substrate-Induced and Thin-Film Phases: Polymorphism of Organic Materials on Surfaces
TL;DR: In this paper, the role of the substrate in controlling the growth and subsequent structural order has been discussed in detail and the impact of polymorphism on organic electronic device properties has been addressed.
Journal ArticleDOI
Thin-Film Morphology of Inkjet-Printed Single-Droplet Organic Transistors Using Polarized Raman Spectroscopy: Effect of Blending TIPS-Pentacene with Insulating Polymer
David James,B. K. Charlotte Kjellander,Wiljan T. T. Smaal,Gerwin H. Gelinck,Craig Combe,Iain McCulloch,Richard Wilson,Jeremy Burroughes,Donal D. C. Bradley,Ji-Seon Kim,Ji-Seon Kim +10 more
TL;DR: Thin-film morphology studies of inkjet-printed single-droplet organic thin-film transistors (OTFTs) are reported using angle-dependent polarized Raman spectroscopy to determine the degree of molecular order and to spatially resolve the orientation of the conjugated backbones of the 6,13-bis(triisopropylsilylethynyl)pentacene (TIPS-Pentacene) molecules.
Journal ArticleDOI
What Currently Limits Charge Carrier Mobility in Crystals of Molecular Semiconductors
TL;DR: In this article, an overview of the best performing molecular semiconductors is constructed based on the question: What currently limits charge carrier mobility in crystals of molecular semiconductor devices? And the current theoretical understanding to the most salient experimental results with the hope to reach a deeper understanding based on first principles and order of magnitudes of the main physical parameters.
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Pentacene organic field-effect transistors with polymeric dielectric interfaces: Performance and stability
TL;DR: In this article, the performance of low-voltage pentacene organic field effect transistors (OFETs) with different gate dielectric interfaces is compared and their performance in terms of electrical properties and operational stability is compared.
References
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Organic Thin Film Transistors for Large Area Electronics
TL;DR: In this article, the authors present new insight into conduction mechanisms and performance characteristics, as well as opportunities for modeling properties of organic thin-film transistors (OTFTs) and discuss progress in the growing field of n-type OTFTs.
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Aromatic-aromatic interaction: a mechanism of protein structure stabilization
TL;DR: Analysis of neighboring aromatic groups in four biphenyl peptides or peptide analogs and 34 proteins reveals a specific aromatic-aromatic interaction that helps stabilize tertiary structure, and 20 percent stabilize quaternary structure.