P. Srivastava

Bio: P. Srivastava is an academic researcher from Centre national de la recherche scientifique. The author has contributed to research in topics: Chemistry & Polypyrrole. The author has an hindex of 11, co-authored 12 publications receiving 2647 citations.

All-polymer field-effect transistor realized by printing techniques

Abstract: A field-effect transistor has been fabricated from polymer materials by printing techniques. The device characteristics, which show high current output, are insensitive to mechanical treatments such as bending or twisting. This all-organic flexible device, realized with mild techniques, opens the way for large-area, low-cost plastic electronics.

Polymorphism and Charge Transport in Vacuum-Evaporated Sexithiophene Films

Abstract: The influence of deposition temperature on structure, orientation, and morphology of vacuum-evaporated sexithiophene films has been studied by using X-ray diffraction, UVvisible spectroscopy and scanning electron microscopy. We correlate this with the mobility of these films as measured in field-effect transistors. The X-ray study based on meridional 001 reflections shows evidence for various crystalline phases depending on the substrate temperature during vapor deposition. A high degree of orientation can be achieved even in several-micrometer-thick films deposited above 190 "C. It is shown that the field-effect mobility is substantially enhanced for deposition temperatures close to the melting point (290 "C), which is associated with a suitable orientation (002 being the single contact plane) and eventually a favorable crystalline structure and coalescent lamellae morphology.

Exciton Coupling Effects in the Absorption and Photoluminescence of Sexithiophene Derivatives

Abstract: published in Advance ACS Abstracts, May 1, 1995. du Markcha1 Joffre, 92002 Nantene, France. 0022-365419512099-9155$09.00/0 SCHEME 1: Chemical Structure of Sexithiophene Derivatives 6T DH6T ClOH21 ClOH21 DD6T have been widely discussed in the literature, and particularly in the case of sexithiophene (6T), very little work has been carried out on the optical characteristics of 6T, and the energetic diagram of this compound is still an object of debate. From photoluminescence measurements under one- and two-photon excitation on a polycrystalline thin film of 6T, an electronic level ordering has been proposed by Taliani et al. in which it is suggested that the lowest Ag exciton level lies at 898 cm-’ above the lowest one-photon-allowed lB, exciton leveL4 Athouel et al. have reported that the n-n* transition in p-sexiphenyl is affected by orientation of these molecules in a thin film.5 Hamano et al. have fabricated molecular oriented thin films of 6T by organic molecular beam deposition.

Electroluminescence in conjugated polymers

Abstract: Research in the use of organic polymers as the active semiconductors in light-emitting diodes has advanced rapidly, and prototype devices now meet realistic specifications for applications. These achievements have provided insight into many aspects of the background science, from design and synthesis of materials, through materials fabrication issues, to the semiconductor physics of these polymers.

Organic Thin Film Transistors for Large Area Electronics

Abstract: Organic thin-film transistors (OTFTs) have lived to see great improvements in recent years. This review presents new insight into conduction mechanisms and performance characteristics, as well as opportunities for modeling properties of OTFTs. The shifted focus in research from novel chemical structures to fabrication technologies that optimize morphology and structural order is underscored by chapters on vacuum-deposited and solution-processed organic semiconducting films. Finally, progress in the growing field of the n-type OTFTs is discussed in ample detail. The Figure, showing a pentacene film edge on SiO2, illustrates the morphology issue.

Materials and mechanics for stretchable electronics

Abstract: Recent advances in mechanics and materials provide routes to integrated circuits that can offer the electrical properties of conventional, rigid wafer-based technologies but with the ability to be stretched, compressed, twisted, bent, and deformed into arbitrary shapes. Inorganic and organic electronic materials in microstructured and nanostructured forms, intimately integrated with elastomeric substrates, offer particularly attractive characteristics, with realistic pathways to sophisticated embodiments. Here, we review these strategies and describe applications of them in systems ranging from electronic eyeball cameras to deformable light-emitting displays. We conclude with some perspectives on routes to commercialization, new device opportunities, and remaining challenges for research.

Charge transport in organic semiconductors.

Abstract: 2.2. Materials 929 2.3. Factors Influencing Charge Mobility 931 2.3.1. Molecular Packing 931 2.3.2. Disorder 932 2.3.3. Temperature 933 2.3.4. Electric Field 934 2.3.5. Impurities 934 2.3.6. Pressure 934 2.3.7. Charge-Carrier Density 934 2.3.8. Size/molecular Weight 935 3. The Charge-Transport Parameters 935 3.1. Electronic Coupling 936 3.1.1. The Energy-Splitting-in-Dimer Method 936 3.1.2. The Orthogonality Issue 937 3.1.3. Impact of the Site Energy 937 3.1.4. Electronic Coupling in Oligoacene Derivatives 938

Conjugated polymer-based chemical sensors.

Abstract: When considering new sensory technologies one should look to nature for guidance. Indeed, living organisms have developed the ultimate chemical sensors. Many insects can detect chemical signals with perfect specificity and incredible sensitivity. Mammalian olfaction is based on an array of less discriminating sensors and a memorized response pattern to identify a unique odor. It is important to recognize that the extraordinary sensory performance of biological systems does not originate from a single element. In actuality, their performance is derived from a completely interactive system wherein the receptor is served by analyte delivery and removal mechanisms, selectivity is derived from receptors, and sensitivity is the result of analyte-triggered biochemical cascades. Clearly, optimal artificial sensory sys-