3.2. Intermolecular Interactions 4840 3.3. Single-Crystal OFETs 4841 3.3.1. Fabrication 4841 3.3.2. Crystal Anisotropy 4842 3.3.3. Patterning of Single Crystals 4843 3.4. Correlation of Crystal Structure with Mobility in TTF Derivatives 4843 4. Polymorphism 4844 4.1. Pentacene and Related Acenes 4845 4.2. Oligothiophenes 4847 4.3. Tetrathiafulvalenes 4849 5. Influence of the Interfaces 4850 5.1. Organic Semiconductor/Dielectric Interface 4850 5.2. Organic Semiconductor/Metal Interface 4852 6. Summary 4852 Author Information 4852 Biographies 4852 Acknowledgment 4853 References 4853

Role of Molecular Order and Solid-State Structure in Organic Field-Effect Transistors

Carbene Ligands in Surface Chemistry: From Stabilization of Discrete Elemental Allotropes to Modification of Nanoscale and Bulk Substrates

Organic electronics have emerged as a viable competitor to amorphous silicon for the active layer in low-cost electronics. The critical performance of organic electronic materials is closely related to their morphology and molecular packing. Unlike their inorganic counterparts, polymers combine complex repeat unit structure and crystalline disorder. This combination prevents any single technique from being able to uniquely solve the packing arrangement of the molecules. Here, a general methodology for combining multiple, complementary techniques that provide accurate unit cell dimensions and molecular orientation is described. The combination of measurements results in a nearly complete picture of the organic film morphology.

Molecular characterization of organic electronic films.

Electronics and Optoelectronics Junliang Yang,*,†,‡ Donghang Yan, and Tim S. Jones †Institute of Super-microstructure and Ultrafast Process in Advanced Materials and ‡Hunan Key Laboratory for Super-microstructure and Ultrafast Process, School of Physics and Electronics, Central South University, Changsha, Hunan 410083, People’s Republic of China State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, Jilin 130022, People’s Republic of China Department of Chemistry, University of Warwick, Coventry CV4 7AL, United Kingdom

Molecular template growth and its applications in organic electronics and optoelectronics.

Bulk gold metal powder, consisting of particles (5−50 μm) much larger than nanoparticles, catalyzes the coupling of carbenes generated from diazoalkanes (R2C═N2) and 3,3-diphenylcyclopropene (DPCP) to form olefins. It also catalyzes cyclopropanation reactions of these carbene precursors with styrenes. The catalytic activity of the gold powder depends on the nature of the gold particles, as determined by TEM and SEM studies. The reactions can be understood in terms of mechanisms that involve the generation of carbene R2C: intermediates adsorbed on the gold surface.

https://lib.dr.iastate.edu/cgi/viewcontent.cgi?article=1368&context=ameslab_pubs

Catalytic Reactions of Carbene Precursors on Bulk Gold Metal

Oriented growth of rubrene thin films on aligned pentacene buffer layer and its anisotropic thin-film transistor characteristics

We have achieved a growth of highly oriented crystalline pentacene thin films, with preferred a−b in-plane orientation with respect to the rubbing direction of a rubbed polymethylene surface. The polymethylene thin film, generated on a gold surface by gold-catalyzed decomposition of diazomethane, was annealed and gently rubbed in a fixed direction by a flannelette cloth to serve as an alignment layer during the deposition of pentacene molecules. Various surface analysis techniques, including reflection absorption IR spectroscopy (RAIRS), near-edge X-ray absorption fine structure (NEXAFS) spectroscopy, grazing incidence X-ray diffraction (GIXD), and atomic force microscopy were used to elucidate the structural details of the polymethylene and the pentacene thin films deposited on it. Two crystalline morphologies of pentacene thin film were observed:  the minor one of rod-like molecular crystals having their long axes of the crystals perpendicular to the rubbing direction, and the dominant one of platelet-l...

Heng-Jui Liu

Papers

Oriented growth of rubrene thin films on aligned pentacene buffer layer and its anisotropic thin-film transistor characteristics

Oriented Growth of Crystalline Pentacene Films with Preferred a-b in-Plane Alignment on a Rubbed Crystalline Polymethylene Surface