Search results for "Diodes"
showing 10 items of 70 documents
High‐Quality Si‐Doped β‐Ga 2 O 3 Films on Sapphire Fabricated by Pulsed Laser Deposition
2020
The EU Horizon 2020 project CAMART2 is acknowledged for partly supporting the project, and the Ion Technology Centre, ITC, in Sweden is acknowledged for ion beam analysis (ERDA).
Current Spreading Length and Injection Efficiency in ZnO/GaN-Based Light-Emitting Diodes
2019
We report on carrier injection features in light-emitting diodes (LEDs) based on nonintentionally doped-ZnO/p-GaN heterostructures. These LEDs consist of a ZnO layer grown by chemical-bath deposition (CBD) onto a p-GaN template without using any seed layer. The ZnO layer (~1- $\mu \text{m}$ thickness) consists of a dense collection of partially coalesced ZnO nanorods, organized in wurtzite phase with marked vertical orientation, whose density depends on the concentration of the solution during the CBD process. Due to the limited conductivity of the p-GaN layer, the recombination in the n-region is strongly dependent on the spreading length of the holes, ${L}_{h}$ , coming from the p-contact…
Energy transduction and signal averaging of fluctuating electric fields by a single protein ion channel
2016
[EN] We demonstrate the electrical rectification and signal averaging of fluctuating signals using a biological nanostructure in aqueous solution: a single protein ion channel inserted in the lipid bilayer characteristic of cell membranes. The conversion of oscillating, zero time-average potentials into directional currents permits charging of a load capacitor to significant steady-state voltages within a few minutes in the case of the outer membrane porin F (OmpF) protein, a bacterial channel of Escherichia coli. The experiments and simulations show signal averaging effects at a more fundamental level than the traditional cell and tissue scales, which are characterized by ensembles of many…
Hybrid perovskites for light-emitting and photovoltaic devices
2017
El objetivo de esta tesis es el desarrollo de métodos y materiales apropiados para la preparación de capas delgadas de perovskitas híbridas, y su implementación en dispositivos optoelectrónicos. Se dedicará particular atención a las relaciones entre la naturaleza del material, el método de deposición y las propiedades optoelectrónicas. El trabajo está organizado como sigue: - Células solares de perovskitas preparadas por evaporación flash. Se desarrolla un simple método de evaporación por la preparación de células solares. - Dispositivos de perovskita con alta eficiencia fotovoltaica y electroluminiscente. En este capítulo se presentan dispositivos optoelectrónicos de perovskitas preparados…
Calibration of the photon spectrometer PHOS of the ALICE experiment
2019
Journal of Instrumentation 14(05), P05025 - P05025 (2019). doi:10.1088/1748-0221/14/05/P05025
The FRAM robotic telescope for atmospheric monitoring at the Pierre Auger Observatory
2021
FRAM (F/Photometric Robotic Atmospheric Monitor) is a robotic telescope operated at the Pierre Auger Observatory in Argentina for the purposes of atmospheric monitoring using stellar photometry. As a passive system which does not produce any light that could interfere with the observations of the fluorescence telescopes of the observatory, it complements the active monitoring systems that use lasers. We discuss the applications of stellar photometry for atmospheric monitoring at optical observatories in general and the particular modes of operation employed by the Auger FRAM. We describe in detail the technical aspects of FRAM, the hardware and software requirements for a successful operati…
Eye tracking analysis of minor details in films for audio description
2012
This article focuses on the many instances when minute details found in feature films may have direct implications upon the development of both the visual and plot narratives. The main question we would like to ask examines whether very subtle details which may easily go unnoticed by the viewer should be audio described. To assess the visual consciousness of such minute details, a perception experiment was conducted using eye-tracking technology and questionnaires. Though the result is not conclusive, it shows a clear methodological approach in the field of the audio description of visual details, and does give some indication as to what should be taken into consideration in future studies …
Multi-sensory approaches to (audio) describing the visual arts
2012
Making art accessible to blind patrons requires the ability to convey explicit and implicit visual messages through non-visual forms. Audio description is often seen as the best way to offer visual texts to blind people; however, one may query whether words alone are sufficient to convey the subtleties of art and to transport the emotional charge such works offer. It is a fact that the dialogue between words and touch may allow these particular “readers” to “see” art in its tangible forms, but perhaps more is needed if one is to give them the opportunity to live the art experience to the full. This article discusses different multi-sensory approaches to making art available to visually impa…
Lyrics against images: music and audio description
2012
Music has been an integral part of films from as far back as the silent movie era, where a piano accompaniment was used to build the narrative and an orchestra was used to drown out the sound of the projector. Music in films can encompass a wide array of elements, from a song to a whistle, and can play many roles, as has been commented upon by many researchers. Due to the relevance of music in film narrative, it is an element which merits attention when it comes to making a film accessible, be it through Audio description, Audio subtitling, Sign Language or Subtitling for the Deaf and Hard-of-Hearing. This article focuses on Audio description (AD) and how music is handled in audio described…
Morphological, electrical and optical properties of organic light-emitting diodes with a LiF/Al cathode and an Al-hydroxyquinoline/diamine junction
2004
Abstract We report the results of the morphological, electrical and optical characterisation of double-layer Alq3-based organic emitting diodes with a lithium fluoride (LiF)/Al cathode. A detailed electron microscopy investigation of their cross-section shows the presence of LiF isolated grains underneath the Al film. Due to the introduction of the LiF layer, luminance was larger than 30,000 cd/m2 at a bias voltage VB=25 V with a maximum external luminous efficiency as large as 46 lm/W at VB=20 V. Performing on/off VB cycles at a very low frequency, each time a recovery of the initial electric and luminous performance was observed. The non-exponential decay of both electric current and lumi…