Indium tin oxide (ITO) is the current standard state‐of‐the‐art transparent conductive oxide (TCO), given its remarkable optical and electrical properties. However, the scarcity of indium carries an important drawback for the long‐term application due to its intensive use in many optoelectronic devices such as displays, solar cells, and interactive systems. Zinc oxide‐based TCOs can be a cost‐effective and viable alternative, but the limitations imposed by their transmittance versus resistivity tradeoff still keep them behind ITO. In this work, an in‐depth study of the structural and compositional material changes induced by specific postannealing treatments is presented, based on aluminum zinc oxide (AZO) and hydrogenated AZO (AZO:H) thin films grown by rf‐magnetron sputtering at room temperature that allows an extensive understanding of the films' electrical/structural changes and the ability to tune their physical parameters to yield increasingly better performances, which put them in line with the best ITO quality standards. The present investigation comprises results of thermal annealing at atmospheric pressure, vacuum, forming gas, H2 and Ar atmospheres and plasmas. Overall the study being performed leads to a decrease in resistivity above 40%, reaching ρ ≈ 3 × 10−4 Ω cm, with an average optical transmittance in the visible region around 88%. Such results are equivalent to the properties of state‐of‐the‐art ITO.
The adsorption equilibrium properties of supercritical methane in the large-pore (lp) structure of the MIL-53(Al) metal organic framework were studied experimentally by gravimetric adsorption and theoretically by grand canonical Monte Carlo (GCMC) simulation. The adsorption experiments span a broad range of pressures (0.01–7 MPa) and temperatures (303–353 K). In our molecular simulation work, MIL-53lp(Al) is assumed to have a perfect, rigid lattice, and both fluid–fluid and solid–fluid interactions are modeled using the TraPPE-UA force field. The adsorption isotherms and isosteric heats of adsorption predicted by GCMC simulation, without any reparametrization of the TraPPE-UA force field parameters, are in good agreement with the experimental measurements. Our molecular simulations predict that the amount of methane adsorbed in the porous framework of MIL-53lp(Al) at 298.15 K and 3.5 MPa is 5.79 mol/kg, yielding a methane storage capacity of 132.6 v/v (volumes of stored gas, measured at standard conditions, per storage volume) for a monolithic block and 107.2 v/v for the theoretical limit of a close-packing of uniform spherical particles. For an isothermal (298.15 K) discharge cycle between 3.5 and 0.136 MPa, the predicted net deliverable capacity is 114.0 (v/v)net for a monolith and 93.1 (v/v)net for a close-packed bed. If, however, the storage system is operated at 253 K, the net storage capacity of a monolithic block of MIL-53(Al) increases to a value that is very close to the DOE target of 150 (v/v)net.
The intense light scattered from metal nanoparticles sustaining surface plasmons makes them attractive for light trapping in photovoltaic applications. However, a strong resonant response from nanoparticle ensembles can only be obtained if the particles have monodisperse physical properties. Presently, the chemical synthesis of colloidal nanoparticles is the method that produces the highest monodispersion in geometry and material quality, with the added benefits of being low-temperature, low-cost, easily scalable and of allowing control of the surface coverage of the deposited particles. In this paper, novel plasmonic back-reflector structures were developed using spherical gold colloids with appropriate dimensions for pronounced far-field scattering. The plasmonic back reflectors are incorporated in the rear contact of thin film n-i-p nanocrystalline silicon solar cells to boost their photocurrent generation via optical path length enhancement inside the silicon layer. The quantum efficiency spectra of the devices revealed a remarkable broadband enhancement, resulting from both light scattering from the metal nanoparticles and improved light incoupling caused by the hemispherical corrugations at the cells' front surface formed from the deposition of material over the spherically shaped colloids.
Nowadays there is a strong demand for intelligent packaging to provide comfort, welfare and security to owners, vendors and consumers by allowing them to know the contents and interact with the goods.
A laboratory-based methodology was designed to assess the bioreceptivity of glazed tiles. The experimental set-up consisted of multiple steps: manufacturing of pristine and artificially aged glazed tiles, enrichment of phototrophic microorganisms, inoculation of phototrophs on glazed tiles, incubation under optimal conditions and quantification of biomass. In addition, tile intrinsic properties were assessed to determine which material properties contributed to tile bioreceptivity. Biofilm growth and biomass were appraised by digital image analysis, colorimetry and chlorophyll a analysis. SEM, micro-Raman and micro-particle induced X-ray emission analyses were carried out to investigate the biodeteriorating potential of phototrophic microorganisms on the glazed tiles. This practical and multidisciplinary approach showed that the accelerated colonization conditions allowed different types of tile bioreceptivity to be distinguished and to be related to precise characteristics of the material. Aged tiles showed higher bioreceptivity than pristine tiles due to their higher capillarity and permeability. Moreover, biophysical deterioration caused by chasmoendolithic growth was observed on colonized tile surfaces.
212941365 ** The first two authors contributed equally to this work.The post-deposition modification of ZnO-based transparent conductive oxides (TCOs) can be the key to produce thin films with optoelectronic properties similar to indium tin oxide (ITO), but at a much lower cost. Here, we present electrooptical results achieved for post-deposition annealing of Al-Zn-O (AZO), AZO:H, Ga-Zn-O:H (GZO:H), and Zn-O:H (ZNO:H) thin films deposited by RF sputtering at room temperature. These studies comprise results of thermal annealing at atmospheric pressure, vacuum, forming gas, H 2 and Ar atmospheres, and H 2 and Ar plasmas, which lead to significant enhancement of their electro-optical properties, which are correlated to morphological and structural improvements. The post-deposition annealing leads to an enhancement in resistivity above 40% for AZO, AZO:H, and GZO:H, reaching r % 2.6-3.5 Â 10 À4 Vcm, while ZnO:H showed a lower improvement of 13%. The averaged optical transmittance in the visible region is about 89% for the investigated TCOs. Such results match the properties of state-of-art ITO (r % 10 À4 Vcm and transmittance in VIS range of 90%) employing much more earth-abundant materials.
In the presented work, the parameters of a new MAPD-3NM-II photodiode with buried pixel structure manufactured in cooperation with Zecotek Company are investigated. The photon detection efficiency, gain, capacitance and gamma-ray detection performance of photodiodes are studied. The SPECTRIG MAPD is used to measure the parameters of the MAPD-3NM-II and scintillation detector based on it. The obtained results show that the newly developed MAPD-3NM-II photodiode outperforms its counterparts in most parameters and it can be successfully applied in space application, medicine, high-energy physics and security.
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