Influence of the gate leakage current on the stability of organic single-crystal field-effect transistors

We investigate the effect of a small leakage current through the gate insulator on the stability of organic single-crystal field-effect transistors (FETs). We find that, irrespective of the specific organic molecule and dielectric used, leakage current flowing through the gate insulator results in an irreversible degradation of the single-crystal FET performance. This degradation occurs even when the leakage current is several orders of magnitude smaller than the source-drain current. The experimental data indicate that a stable operation requires the leakage current to be smaller than $10^{-9} \ \mathrm{A/cm}^2$. Our results also suggest that gate leakage currents may determine the lifetime of thin-film transistors used in applications.Comment: submitted to Appl. Phys. Let

Highlights from the Faraday discussion on new directions in porous crystalline materials, Edinburgh, UK, June 2017

A lively discussion on new directions in porous crystalline materials took place in June 2017, with the beautiful city of Edinburgh as a backdrop, in the context of the unique Faraday Discussions format. Here, 5 minute presentations were given on papers which have been submitted in advance of the conference, with copious time allocated for in-depth discussion of the work presented. Professor Mircea Dincă (MIT), chair of the scientific committee, opened the conference by welcoming the many different nationalities attending, and outlining the format of discussions

High precision beam momentum determination in a synchrotron using a spin resonance method

In order to measure the mass of the eta meson with high accuracy using the d+p -> 3He+eta reaction, the momentum of the circulating deuteron beam in the Cooler Synchrotron COSY of the Forschungszentrum Juelich has to be determined with unprecedented precision. This has been achieved by studying the spin dynamics of the polarized deuteron beam. By depolarizing the beam through the use of an artificially induced spin resonance, it was possible to evaluate its momentum p with a precision of dp/p < 10-4 for a momentum of roughly 3 GeV/c. Different possible sources of error in the application of the spin resonance method are discussed in detail and its possible use during a standard experiment is considered.Comment: 10 pages, 6 figures, 2 tables, published versio

Improving the mechanical stability of zirconium-based metal-organic frameworks by incorporation of acidic modulators

Acidic modulating ligands have been shown to stabilize UiO metal-organic frameworks against structural collapse under ball-milling.T.D.B. would like to thank Trinity Hall for funding, along with Professor Anthony K. Cheetham for use of lab facilities. D.D.V. is grateful to IWT (MOF Shape), KU Leuven for support in the Metusalem grant CASAS and IAP 7/05 Functional Supramolecular Systems. I.S. and B.B. thank Research Foundation – Flanders (FWO) for Ph.D. fellowships.This is the accepted manuscript. The final published version is available from RSC at http://pubs.rsc.org/en/Content/ArticleLanding/2015/TA/c4ta06396a#!divAbstract

No association of a set of candidate genes on haloperidol side effects

We previously investigated a sample of patients during an active phase of psychosis in the search for genetic predictors of haloperidol induced side effects. In the present work we extend the genetic association analysis to a wider panel of genetic variations, including 508 variations located in 96 genes. The original sample included 96 patients. An independent group of 357 patients from the CATIE study served as a replication sample. Outcomes in the investigation sample were the variation through time of: 1) the ESRS and UKU total scores 2) ESRS and UKU subscales (neurologic and psychic were included) related to tremors and 3) ESRS and UKU subscales that do not relate to tremors. Outcome in the replication sample was the presence vs absence of motoric side effects from baseline to visit 1 ( 3c one month of treatment) as assessed by the AIMS scale test. Rs2242480 located in the CYP3A4 was associated with a different distribution of the UKU neurologic scores through time (permutated p\u200a=\u200a0.047) along with a trend for a different haloperidol plasma levels (lower in CC subjects). This finding was not replicated in the CATIE sample. In conclusion, we did not find conclusive evidence for a major association between the investigated variations and haloperidol induced motoric side effect

Measurement of the analysing power in proton-proton elastic scattering at small angles

The proton analysing power in $\vec{p}p$ elastic scattering has been measured at small angles at COSY-ANKE at 796 MeV and five other beam energies between 1.6 and 2.4 GeV using a polarised proton beam. The asymmetries obtained by detecting the fast proton in the ANKE forward detector or the slow recoil proton in a silicon tracking telescope are completely consistent. Although the analysing power results agree well with the many published data at 796 MeV, and also with the most recent partial wave solution at this energy, the ANKE data at the higher energies lie well above the predictions of this solution at small angles. An updated phase shift analysis that uses the ANKE results together with the World data leads to a much better description of these new measurements.Comment: 5 pages, 3 figure

Measurement of the absolute differential cross section of proton-proton elastic scattering at small angles

The differential cross section for proton-proton elastic scattering has been measured at a beam energy of 1.0 GeV and in 200 MeV steps from 1.6 to 2.8 GeV for centre-of-mass angles in the range from 12-16 degrees to 25-30 degrees, depending on the energy. Absolute normalisations of typically 3% were achieved by studying the energy losses of the circulating beam of the COSY storage ring as it passed repeatedly through the windowless hydrogen target of the ANKE magnetic spectrometer. It is shown that the data have a significant impact upon a partial wave analysis. After extrapolating the differential cross sections to the forward direction, the results are broadly compatible with the predictions of forward dispersion relations

Measurement of the analyzing powers in pd elastic and pn quasi-elastic scattering at small angles

The analyzing powers in proton-deuteron elastic and proton-neutron quasi-elastic scattering have been measured at small angles using a polarized proton beam at the COSY storage ring incident on an unpolarized deuterium target. The data were taken at 796MeV and five higher energies from 1600MeV to 2400MeV. The analyzing power in pd elastic scattering was studied by detecting the low energy recoil deuteron in telescopes placed symmetrically in the COSY plane to the left and right of the beam whereas for pn quasi-elastic scattering a low energy proton was registered in one of the telescopes in coincidence with a fast scattered proton measured in the ANKE magnetic spectrometer. Though the experiment explores new domains, the results are consistent with the limited published information.Comment: 10 pages with 8 figure

Towards metal-organic framework based field effect chemical sensors: UiO-66-NH2 for nerve agent detection

We present a highly sensitive gas detection approach for the infamous 'nerve agent' group of alkyl phosphonate compounds. Signal transduction is achieved by monitoring the work function shift of metal-organic framework UiO-66-NH2 coated electrodes upon exposure to ppb-level concentrations of a target simulant. Using the Kelvin probe technique, we demonstrate the potential of electrically insulating MOFs for integration in field effect devices such as ChemFETs: a three orders of magnitude improvement over previous work function-based detection of nerve agent simulants. Moreover, the signal is fully reversible both in dry and humid conditions, down to low ppb concentrations. Comprehensive investigation of the interactions that lead towards this high sensitivity points towards a series of confined interactions between the analyte and the pore interior of UiO-66-NH2