1,720,981 research outputs found

    Flexible Organic Phototransistors With Limit of Detection Down to 28 pW/cm2

    No full text
    Over the past few years, most applications in the field of light sensing have required devices able to detect light intensities as low as pW/cm2. At the same time, the rise of organic-based sensors is meeting no stops because of the desired properties that organic materials provide, like flexibility, lightweight, low cost, and low temperature processability. Low-intensity light signal detectors are growing in a huge number of fields. In prostate cancer treatment, modern proton therapy requires the detection of very low light intensities generated by scintillators that convert the proton flux into a light signal; moreover, in robotics, the most recent products need to detect light both in the sunlight and at nighttime, when the illumination intensity is lower. Here, we report on a flexible organic phototransistor (OPT) with impressive low-light detection, with a limit of detection (LoD) down to 28 pW/cm2. The OPT works reliably in different environments, acting at low polarization bias down to -1 V. These results show the perspective of a new class of light detectors based on a low-cost manufacturing process for flexible applications

    POSSIBLE EVIDENCE OF QUANTUM-SIZE EFFECTS IN X-RAY PHOTOEMISSION SPECTRA OF ULTRATHIN SI LAYERS

    No full text
    This letter reports the experimental evidence of a 2.3 eV blue shift of the plasmon loss lines observed in the x-ray photoelectron spectra of an ultrathin Si layer equivalent to 1.5 X 10(15) at./cm(2) deposited onto a randomly oriented Al2O3 Single crystal. The plasmon line shifts, which is roughly proportional to the deposited Si(mass)(-2/3), are attributed to quantum confinement effects in agreement with electron energy loss measurements performed on nanosized Si particles

    Going Beyond Counting First Authors in Author Co-citation Analysis

    Full text link
    The present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed

    Variations on the Author

    Full text link
    “Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
    corecore