Search results for " Thin film"
showing 10 items of 102 documents
Fabrication and Characterisation of Perovskite Thin Films for Photovoltaic Application
2018
This paper presents an alternative way to obtain perovskite thin films for photovoltaic application. This technique results more competitive, scalable, low-cost, reproducible and is different from other most common methods of fabrication.
Bending Sensors Based on Thin Films of Semitransparent Bithiophene-Fulleropyrrolidine Bisadducts
2020
In this study, a novel bithiophene‐fulleropyrrolidine bisadducts system (bis‐Th2PC 60 ) was synthesized and electropolymerized by chronoamperometry onto flexible ITO/PET substrates. The resulting semitransparent thin film was characterized by XPS, FT‐IR, cyclic voltammetry and optical techniques, confirming the good outcome of the electropolymerization process. AFM investigations permitted to highlight an inherent disordered granular morphology, in which the grain‐to‐grain separation depends upon the application of bending. The electrical resistance of the thin film was characterized as function of bending (in the range 0°‐90°), showing promising responsivity to low bending angles (10°‐30°)…
Metal thin-film temperature sensor embedded in heat-sink for CPV cells characterization
2014
The efficiency of a photovoltaic cell is dependent on its temperature, for this reason an accurate measurement of this parameter is important to fully characterize the device and to optimize its performance. For CPV applications a significant heat flux is needed to remove excess heat from the cell towards a heat sink, making it difficult to derive the cell temperature. In fact, measurements performed directly between the cell and the heat-sink, by use of commercial bulk sensors, would produce a significant disturbance in the heat flow; on the other hand, a measurement performed out of the cell / heat sink axis would be subject to large uncertainties, due to the high radial temperature gradi…
Enhanced Magneto-optic Kerr Effect and Magnetic Properties ofCeY2Fe5O12Epitaxial Thin Films
2015
Integrated magneto-optical components require magnetic thin films for tuning of their parameters, and for many applications yttrium iron garnet (YIG) is the material of choice. The authors study high-quality cerium-substituted YIG thin films grown by pulsed laser deposition, which possess tunable magnetic anisotropy and a greatly enhanced magneto-optic Kerr effect, compared to conventional films. This discovery presents new opportunities for engineering tomorrow's magneto-optical and spintronic logic devices.
Surface magnetic structure investigation of a nanolaminated Mn$_2$GaC thin film using a magnetic field microscope based on Nitrogen-Vacancy centers
2021
This work presents a magnetic field imaging method based on color centers in diamond crystal applied to a thin film of a nanolaminated Mn$_2$GaC MAX phase. Magnetic properties of the surface related structures have been described around the first order transition at 214 K by performing measurements in the temperature range between 200 K and 235 K with the surface features fading out by increasing temperature above the transition temperature. The results presented here demonstrate how Nitrogen-Vacancy center based magnetic microscopy can supplement the traditionally used set of experimental techniques, giving additional information of microscopic scale magnetic field features, and allowing t…
Characterization of microscopic ferromagnetic defects in thin films using magnetic microscope based on Nitrogen-Vacancy centres
2020
In this work we present results acquired by applying magnetic field imaging technique based on Nitrogen-Vacancy centres in diamond crystal for characterization of magnetic thin films defects. We used the constructed wide-field magnetic microscope for measurements of two kinds of magnetic defects in thin films. One family of defects under study was a result of non-optimal thin film growth conditions. The magnetic field maps of several regions of the thin films created under very similar conditions to previously published research revealed microscopic impurity islands of ferromagnetic defects, that potentially could disturb the magnetic properties of the surface. The second part of the measur…
Effects of electrolyte doping on electrodeposited nanostructured manganese oxide and chromium oxide
2020
Abstract Electrolyte additions are used to control the functionality of a nanostructured oxide. Dopant ions affect the size and shape of deposit crystallites and modify the host structure. Such ions can be incorporated into the deposit or form a separate oxide phase. The manganese dioxide family of polymorphs with ion-molecular sieve properties represents the additional possibilities of “template” effects of dopant ions on the phase composition, heterovalent substitution in the cationic sublattice, changes in morphology and alteration of nanocrystallite size during electrocrystallisation. The effects of electrolyte doping in electrodeposited, non-stoichiometric manganese dioxide (NH4+, Li+ …
Efficient photoluminescent thin films consisting of anchored hybrid perovskite nanoparticles
2016
Methylammonium lead bromide nanoparticles are synthetized with a new ligand (11-aminoundecanoic acid hydrobromide) by a non-template method. Upon dispersion in toluene they show a remarkable photoluminescence quantum yield of 80%. In addition, the bifunctional ligand allows anchoring of the nanoparticles on a variety of conducting and semiconducting surfaces, showing bright photoluminescence with a quantum yield exceeding 50%. This opens a path for the simple and inexpensive preparation of multilayer light-emitting devices. NRF (Natl Research Foundation, S’pore) ASTAR (Agency for Sci., Tech. and Research, S’pore) Accepted version
Broadband light trapping in thin film solar cells with self-organized plasmonic nano-colloids
2015
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 wi…
Epitaxial Thin-Film vs Single Crystal Growth of 2D Hofmann-Type Iron(II) Materials: A Comparative Assessment of their Bi-Stable Spin Crossover Proper…
2020
Integration of the ON-OFF cooperative spin crossover (SCO) properties of FeII coordination polymers as components of electronic and/or spintronic devices is currently an area of great interest for potential applications. This requires the selection and growth of thin films of the appropriate material onto selected substrates. In this context, two new series of cooperative SCO two-dimensional FeII coordination polymers of the Hofmann-type formulated {FeII(Pym)2[MII(CN)4]·xH2O}n and {FeII(Isoq)2[MII(CN)4]}n (Pym = pyrimidine, Isoq = isoquinoline; MII = Ni, Pd, Pt) have been synthesized, characterized, and the corresponding Pt derivatives selected for fabrication of thin films by liquid-phase …