Unraveling unprecedented charge carrier mobility through structure property relationship of four isomers of didodecyl[1]benzothieno[3,2-b][1]benzothiophene

Since the dawn of organic electronics in the 1970’s, academic and industrial research efforts have led to dramatic improvements of the solubility, stability, and electronic properties of organic semiconductors (OSCs).[1, 2] The common benchmark to characterize the electrical performances of OSCs is their charge carrier mobility μ (cm2 V–1 s–1), defined as the drift velocity of the charge carrier (cm s–1) per unit of applied electric field (V cm–1). Reaching high mobilities in OSCs is highly desirable as it allows faster operation of transistors and energy savings by reduced calculation times.[2, 3] However, OSCs performances (conventional values usually range from 1 to 10 cm2 V–1 s–1, with highest values obtained with single-crystal devices mostly exempt of structural defects) are still not comparable to that of state-of-the-art inorganic semiconductors (e.g. metal oxides with µ = 20-50 cm2 V–1 s–1 and polycrystalline silicon with µ > 100 cm2 V–1 s–1) thereby hampering important potential technological applications such as flexible organic light-emitting diode (OLED) displays and wearable electronics.[3, 4

Determination of halogen abundances in terrestrial and extraterrestrial samples by the analysis of noble gases produced by neutron irradiation

The lack of a reliable database for heavy halogens (bromine and iodine) in terrestrial and extraterrestrial samples is mainly due to the analytical challenges of determining their very low abundances (&lt; 1ppm) in the materials of interest. The neutron irradiation noble gas mass spectrometric (NI-NGMS) technique initially developed in the 1960′s is the only viable technique currently capable of determining concentrations below 1 ppb of iodine for small (&lt; 10mg) sample sizes. We describe in detail the analytical protocols and provide a comprehensive and transparent overview of the data reduction procedures in order to fully explore the uncertainties of the technique. We demonstrate how the capabilities of modern mass spectrometers used for Ar-Ar dating, can be readily extended to incorporate halogen measurements. A new and critical assessment of the use of standards is presented based on results from multiple irradiations, including a meteorite (Shallowater aubrite), scapolite minerals introduced by Kendrick (2012) and a novel internal correction method based on using barium.</p

New insights into the plumbing system of Santorini using helium and carbon isotopes

We have analysed He, Ne and CO2 concentrations and isotopic ratios in seawater samples collected using a ROV above hydrothermal fields and in CO2-accumulating pools within Santorini caldera (Greece). Our results provide new insights on the plumbing and magmatic sources of this volcano, which is critical to understand and better predict its volcanic eruptions, and its relationships to nearby volcanic systems. The 3He/4He ratio is as high as 6.54 times the atmospheric ratio, and significantly higher than any other samples from Santorini, including the active eruptive centre of Nea Kameni (~3.6 Ra). The 3He/4He ratio, corrected for atmospheric helium dissolved in seawater is ~7 Ra, a value similar to that measured at the nearby Kolumbo submarine volcano crater. The fluids display typical mantle signatures never recorded before in the active centres of the island of Santorini, in which fluids and gases are contaminated at shallow depths. The helium isotopic signature suggests that the source of volatiles for these two nstead of being the subcontinental lithospheric mantle as suggested previously. © 2019 The Authors Published by the European Association of Geochemistr

New insights into the plumbing system of Santorini using helium and carbon isotopes

International audienceWe have analysed He, Ne and CO 2 concentrations and isotopic ratios in seawater samples collected using a ROV above hydrothermal fields and in CO 2-accumulating pools within Santorini caldera (Greece). Our results provide new insights on the plumbing and magmatic sources of this volcano, which is critical to understand and better predict its volcanic eruptions, and its relationships to nearby volcanic systems. The 3 He/ 4 He ratio is as high as 6.54 times the atmospheric ratio, and significantly higher than any other samples from Santorini, including the active eruptive centre of Nea Kameni (~3.6 Ra). The 3 He/ 4 He ratio, corrected for atmospheric helium dissolved in seawater is ~7 Ra, a value similar to that measured at the nearby Kolumbo submarine volcano crater. The fluids display typical mantle signatures never recorded before in the active centres of the island of Santorini, in which fluids and gases are contaminated at shallow depths. The helium isotopic signature suggests that the source of volatiles for these two volcanoes is similar to the MORB source instead of being the subcontinental lithospheric mantle as suggested previously

Untangling the Fundamental Electronic Origins of Non-Local Electron–Phonon Coupling in Organic Semiconductors

Funder: ISIS Neutron and Muon SourceOrganic semiconductors with distinct molecular properties and large carrier mobilities are constantly developed in attempt to produce highly‐efficient electronic materials. Recently, designer molecules with unique structural modifications have been expressly developed to suppress molecular motions in the solid state that arise from low‐energy phonon modes, which uniquely limit carrier mobilities through electron–phonon coupling. However, such low‐frequency vibrational dynamics often involve complex molecular dynamics, making comprehension of the underlying electronic origins of electron–phonon coupling difficult. In this study, first a mode‐resolved picture of electron–phonon coupling in a series of materials that are specifically designed to suppress detrimental vibrational effects, is generated. From this foundation, a method is developed based on the crystalline orbital Hamiltonian population (COHP) analyses to resolve the origins—down to the single atomic‐orbital scale—of surprisingly large electron–phonon coupling constants of particular vibrations, explicitly detailing the manner in which the intermolecular wavefunction overlap is perturbed. Overall, this approach provides a comprehensive explanation into the unexpected effects of less‐commonly studied molecular vibrations, revealing new aspects of molecular design that should be considered for creating improved organic semiconducting materials

Comparative studies in series of cytochrome c oxidase models.

International audienceThis study compares the behavior as cytochrome c oxidase (CcO) functional and structural models of a series of reported and unreported ligands that provide either a binding site for copper without a built-in proximal base, or both a flexible binding site for copper and a built-in proximal base, or a fixed binding site for copper with a built-in proximal base. The comparisons of the models show that the relative position of the two metal sites is not only a crucial parameter in the control of the catalytic behavior but also essential in mimicking other features of the enzyme such as CO exchange between the ferrous heme a(3) and the cuprous Cu(B) center