Search results for " Thin Film"
showing 10 items of 102 documents
Electrochemical Tantalum Oxide for Resistive Switching Memories
2017
Redox-based resistive switching memories (ReRAMs) are strongest candidates for the next-generation nonvolatile memories fulfilling the criteria for fast, energy efficient, and scalable green IT. These types of devices can also be used for selector elements, alternative logic circuits and computing, and memristive and neuromorphic operations. ReRAMs are composed of metal/solid electrolyte/metal junctions in which the solid electrolyte is typically a metal oxide or multilayer oxides structures. Here, this study offers an effective and cheap electrochemical approach to fabricate Ta/Ta2O5-based devices by anodizing. This method allows to grow high-quality and dense oxide thin films onto a metal…
Robustness and electrical reliability of AZO/Ag/AZO thin film after bending stress
2017
Abstract The increasing interest in thin flexible and bendable devices has led to a strong demand for mechanically robust and electrically reliable transparent electrodes. Indium doped Tin Oxide (ITO) and Aluminium doped Zinc Oxide (AZO) are among the most employed transparent conductive oxides (TCO) and their reliability on flexible substrates have thus received a great attention. However, a high flexibility is usually achieved at very low thickness, which, unfortunately, compromises the electrical conductivity. Here we report the effects of mechanical bending cycles on the electrical and optical properties of ultra thin AZO/Ag/AZO multilayers (45 nm/10 nm/45 nm) and, for comparison, of AZ…
Nanostructural depth-profile and field-effect properties of poly(alkoxyphenylene-thienylene) Langmuir-Schäfer thin-films
2008
The correlations between morphological features and field-effect properties of poly(alkoxyphenylene-thiophene) thin Langmuir–Schafer film deposited on differently terminated gate dielectric surfaces, namely bare and methyl functionalized thermal silicon dioxide (t-SiO2), have been systematically studied. The film morphology has been investigated at different film thickness by Scanning Force Microscopy. Films thicker than a few layers show comparable morphology on both dielectric surfaces while differences are seen for the ultra-thin polymer deposit in close proximity to the substrate. Such deposit is notably more heterogeneous on bare t-SiO2, while a more compact and uniform nanogranular st…
Plasmonic layers based on Au-nanoparticle-doped TiO2 for optoelectronics: structural and optical properties.
2013
The anti-reflective effect of dielectric coatings used in silicon solar cells has traditionally been the subject of intensive studies and practical applications. In recent years the interest has permanently grown in plasmonic layers based on metal nanoparticles, which are shown to increase light trapping in the underlying silicon. In the present work we have combined these two concepts by means of in situ synthesis of Au nanoparticles in a dielectric matrix (TiO2), which is commonly used as an anti-reflective coating in silicon solar cells, and added the third element: a 10–20% porosity in the matrix. The porosity is formed by means of a controllable wet etching by low concentration HF. As …
Carbon nanotubes and organic solar cells
2012
The use of carbon nanotubes in photovoltaics is still challenging due to different issues connected to their synthesis, purification, functionalization, processing and device integration. From this perspective at first we review on selected contributions dealing with the above issues; then we focus on the advantages and limitations of carbon nanotubes for the development of organic solar cells.
Polymeric Thin Films for Organic Electronics: Properties and Adaptive Structures
2013
This review deals with the correlation between morphology, structure and performance of organic electronic devices including thin film transistors and solar cells. In particular, we report on solution processed devices going into the role of the 3D supramolecular organization in determining their electronic properties. A selection of case studies from recent literature are reviewed, relying on solution methods for organic thin-film deposition which allow fine control of the supramolecular aggregation of polymers confined at surfaces in nanoscopic layers. A special focus is given to issues exploiting morphological structures stemming from the intrinsic polymeric dynamic adaptation under non-…
The effect of annealing temperature and time on synthesis of graphene thin films by rapid thermal annealing
2015
In this paper, we performed synthesis of graphene thin films by rapid thermal annealing (RTA) of thin nickel copper (Ni/Cu) layers deposited on spectroscopic graphite as a carbon source. Furthermore, we investigated the effect of annealing temperature and annealing time on formation and quality of synthesized graphene films. Raman spectroscopy study showed that annealing at lower temperatures results in formation of monolayer graphene films, while annealing at higher temperatures results in formation of multilayer graphene films. We used Raman mapping to determine the distribution of graphene sheets. Surface morphology of graphene thin films was investigated by atomic force microscopy and s…
ELECTRODEPOSITION OF NOVEL POLY(NAPHTHALENEDIIMIDE-QUATERTHIOPHENE) THIN FILMS AND APPLICATIONS IN PLASTIC OPTOELECTRONICS DEVICES
2013
A novel symmetric naphthalenediimide-quaterthiophene derivative (NDIT4d) has been polymerized on different substrates including glassy carbon and ITO/PET electrodes by means of electrochemical methods. XPS and UV-VIS spectroscopy as well as cyclic voltammetry have been employed for characterizing the thin film chemical features, the band gap and the HOMO and LUMO levels. DFT computational studies were in close agreement with the experimental observables also showing intriguing geometrical effects on the band gap energy values. The comparison of the energy levels locations of the electrodeposited poly(naphthalenediimide-quaterthiophene) derivative (e-PNDIT4) and P3HT thin films transferred b…
Regenerable ZnO/GaAs Bulk Acoustic Wave Biosensor for Detection of Escherichia coli in “Complex” Biological Medium
2021
A regenerable bulk acoustic wave (BAW) biosensor is developed for the rapid, label-free and selective detection of Escherichia coli in liquid media. The geometry of the biosensor consists of a GaAs membrane coated with a thin film of piezoelectric ZnO on its top surface. A pair of electrodes deposited on the ZnO film allows the generation of BAWs by lateral field excitation. The back surface of the membrane is functionalized with alkanethiol self-assembled monolayers and antibodies against E. coli. The antibody immobilization was investigated as a function of the concentration of antibody suspensions, their pH and incubation time, designed to optimize the immunocapture of bacteria. The perf…
Flexible Laser Tracing Systems for Defining Thin Film Hybrid Geometries
1994
A recent programme of technical collaboration between Alelco, DIE of Palermo and CRES of Monreale has led to the development and operative confirmation of a technique for delineating conductive microgeometries on various types of Substrates. This technique, using a flexible System of laser microlithography on planar (2-D) or three-dimensional (3-D) surfaces, has led to the development of several types of thin film components for use at both low and high frequencies. © 1994, MCB UP Limited