Search results for "Conductor"
showing 10 items of 1270 documents
Ionic-electronic interaction in optoelectronic and sensing devices
2016
En este trabajo se estudian las interacciones entre cargas electrónicas e iónicas y sus aplicaciones en sensores y dispositivos optoelectrónicos. El mecanismo de funcionamiento de los dispositivos optoelectrónicos actualmente más comunes, como los transistores de efecto de campo de capa fina (TFTs), los diodos emisores de luz (LEDs) y las células solares se basa solamente en procesos electrónicos, lo que significa que los efectos de cargas iónicas están ausentes, son irrelevantes o incluso perjudiciales para el propósito de dichos dispositivos. Sin embargo, muchas aplicaciones se benefician de la presencia de iones en la estructura de un dispositivo. Un ejemplo típico en el campo de investi…
Charge Transport Mechanisms in Heavy-Ion Driven Leakage Current in Silicon Carbide Schottky Power Diodes
2016
Under heavy-ion exposure at sufficiently high reverse bias voltages silicon carbide (SiC) Schottky diodes are observed to exhibit gradual increases in leakage current with increasing ion fluence. Heavy-ion exposure alters the overall reverse current-voltage characteristics of these diodes, leaving the forward characteristics practically unchanged. This paper discusses the charge transport mechanisms in the heavy-ion damaged SiC Schottky diodes. A macro model, describing the reverse current-voltage characteristics in the degraded SiC Schottky diodes is proposed. peerReviewed
NANOWIRES AND THIN FILMS OF CIS/CIGS OBTAINED BY ELECTRODEPOSITION AS ABSORBER FOR SOLAR CELLS
2011
Ti Alloyed α-Ga2O3: Route towards Wide Band Gap Engineering
2020
The suitability of Ti as a band gap modifier for &alpha
Ultrafast Coherent THz Lattice Dynamics Coupled to Spins in the van der Waals Antiferromagnet FePS3
2022
Coherent THz optical lattice and hybridized phonon–magnon modes are triggered by femtosecond laser pulses in the antiferromagnetic van der Waals semiconductor FePS3. The laser-driven lattice and spin dynamics are investigated in a bulk crystal as well as in a 380 nm-thick exfoliated flake as a function of the excitation photon energy, sample temperature and applied magnetic field. The pump-probe magneto-optical measurements reveal that the amplitude of a coherent phonon mode oscillating at 3.2 THz decreases as the sample is heated up to the Néel temperature. This signal eventually vanishes as the phase transition to the paramagnetic phase occurs, thus revealing its connection to the long-ra…
UV Metal Semiconductor Metal Detectors. A Robust Choice for (Al,Ga)N Based Detectors
2004
UV detection is interesting for combustion optimization, air contamination control, fire and solar blind rocket launching detection. Most of these applications require that UV detectors have a huge dynamic response between UV and the visible, and a very low dark current in the range of the UV flux measured. (Al,Ga)N alloys present a large direct bandgap in this range and therefore can be used as an active region in such detectors. To take advantage of the large Schottky barrier, the good alloy quality, and to avoid any doping problems, we have developed MSM photodetectors. High quality material has been grown with MOCVD and MBE on sapphire substrates. Stress management is employed for alumi…
Thermoelectric devices and supercapacitors based on nanostructured semiconducting polymers for energy production and storage
2017
Más de dos terceras partes de la energía generada por las fuentes convencionales se pierden como calor. Recuperar esas pérdidas de energía puede ayudar a crear una forma más eficiente de producir energía para el desarrollo sostenible de nuestra sociedad. Mediante el uso de generadores termoeléctricos es posible producir energía a partir de gradientes de temperatura de tal manera que la termoelectricidad puede ser una buena estrategia para la recolección y recuperación de energía. La eficiencia termoeléctrica suele ser dada por la figura adimensional de mérito, ZT. Actualmente, los materiales inorgánicos se usan comúnmente en aplicaciones termoeléctricas, sin embargo presentan varias desvent…
Quantum fluctuations in superconducting nanostructures
2014
Modern nanofabrication technology enableTfabrication of very narrow quasi-1-dimensional superconducting nanowires demonstrating finite resistivity within the range of experimentally obtainable temperatures. The observations were reported in ∼10 nm nanowires of certain superconducting materials. The effect has been associated with quantum phase slip process - the particular manifestation of quantum fluctuations of the order p arameter. In titanium, the phenomenon can be observed already at dimensions ∼35 nm where the fabrication is well reproducible and the dimensions of samples can be characterized with high accuracy. We have performed systematic study of the size dependence of transport pr…
Field-induced coexistence of s++ and s± superconducting states in dirty multiband superconductors
2018
In multiband systems, such as iron-based superconductors, the superconducting states with locking and antilocking of the interband phase differences are usually considered as mutually exclusive. For example, a dirty two-band system with interband impurity scattering undergoes a sharp crossover between the s± state (which favors phase antilocking) and the s++ state (which favors phase locking). We discuss here that the situation can be much more complex in the presence of an external field or superconducting currents. In an external applied magnetic field, dirty two-band superconductors do not feature a sharp s±→s++ crossover but rather a washed-out crossover to a finite region in the parame…
Chirality selective spin interactions mediated by the moving superconducting condensate
2018
We show that superconducting correlations in the presence of nonzero condensate velocity can mediate the peculiar interaction between localized spins that breaks the global inversion symmetry of magnetic moments. The proposed interaction mechanism is capable of removing fundamental degeneracies between topologically distinct magnetic textures. For the generic system of three magnetic impurities in the current-carrying superconductor, we find the energy term proportional to spin chirality. In realistic superconductor/ferromagnetic/superconductor setups we reveal significant energy differences between various magnetic textures with opposite chiralities. We calculate Josephson energies of junc…