Search results for "thin films"
showing 10 items of 154 documents
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 …
Conductive Fused Porphyrin Tapes on Sensitive Substrates by a Chemical Vapor Deposition Approach.
2019
Abstract Oxidative polymerization of nickel(II) 5,15‐diphenyl porphyrin and nickel(II) 5,15‐bis(di‐3,5‐tert‐butylphenyl) porphyrin by oxidative chemical vapor deposition (oCVD) yields multiply fused porphyrin oligomers in thin film form. The oCVD technique enables one‐step formation, deposition, and p‐doping of conjugated poly(porphyrins) coatings without solvents or post‐treatments. The decisive reactions and side reactions during the oCVD process are shown by high‐resolution mass spectrometry. Owing to the highly conjugated structure of the fused tapes, the thin films exhibit an electrical conductivity of 3.6×10−2 S cm−1 and strong absorption in the visible to near‐infrared spectral regio…
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-…
On the possibility of synthesizing multilayered coatings in the (Ti,Al)N system by RGPP: A microstructural study
2019
International audience; Radiofrequency magnetron sputtering combined with reactive gas pulsing process was used to synthesize two titanium aluminum nitride multilayer films using a periodically controlled nitrogen flow rate changing from 0.4 to 1 sccm (sample S04-1) and from 0 to 1 sccm (sample S0-1). A metallic TiAl buffer layer was deposited on the etched substrates before the deposition to enhance their adhesion. The films were characterized using mainly transmission electron microscopy and electron diffraction. The role of the crystallinity of the buffer TiAl metallic layer deposited before gas introduction on the growth orientations is emphasized. It is shown that the formation of a mu…
Thin Film Organic Thermoelectric Generator Based on Tetrathiotetracene
2017
This is the peer reviewed version of the following article: K. Pudzs, A. Vembris, M. Rutkis, S. Woodward, Adv. Electron. Mater. 2017, 1600429, which has been published in final form at http://onlinelibrary.wi...002/aelm.201600429/full This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving.
Structural and electrical properties of magnetron sputtered Ti(ON) thin films:The case of TiN doped in situ with oxygen.
2009
International audience; Incorporation of oxygen into TiN lattice results in formation of titanium oxynitrides, TiOxNy that have become particularly interesting for photocatalytic applications. Elaboration as well as characterization of TiN and in situ oxygen-doped thin films is the subject of this paper. Thin films, 250–320nm in thickness, have been deposited by dc-pulsed magnetron reactive sputtering from Ti target under controllable gas flows of Ar, N2 and O2. Optical monitoring of Ti plasma emission line at = 500nm has been implemented in order to stabilize the sputtering rate. Scanning electron microscopy (SEM), X-ray diffraction in grazing incidence (GIXRD), micro-Raman spectroscopy, X…
Changes in structure and conduction type upon addition of Ir to ZnO thin films
2017
Zn-Ir-O (Zn/Ir ≈ 1/1) thin films have been reported to be a potential p-type TCO material. It is, however, unknown whether it is possible to achieve p-type conductivity at low Ir content, and how the type and the magnitude of conductivity are affected by the film structure. To investigate the changes in properties taking place at low and moderate Ir content, this study focuses on the structure, electrical and optical properties of ZnO:Ir films with iridium concentration varying between 0.0 and 16.4 at.%. ZnO:Ir thin films were deposited on glass, Si, and Ti substrates by DC reactive magnetron co-sputtering at room temperature. Low Ir content (up to 5.1 at.%) films contain both a nano-crysta…
Anisotropic and non-heterogeneous continuum percolation in titanium oxynitride thin columnar films
2002
International audience; We report the percolation behaviour of the conductivity of titanium oxynitride films grown by low-pressure metal-organic chemical vapour deposition, composed of TiNxOy mixed with TiO2. The usual DC parameters (t, s and Φc), obtained from the effective media theory equations, are compared to the universal values (s = sun while t < tun because of the film anisotropy). This is the first example of an electrical continuum percolation applied to columnar films with chemically similar conducting and insulating units (non-heterogeneous percolation) whose mixing is based upon the growth temperature during the film growth.
Stable n-type thermoelectric multilayer thin films with high power factor from carbonaceous nanofillers
2016
Abstract High power factor n-type organic thermoelectric nanocomposites are assembled by alternately depositing double walled-nanotubes (DWNT), stabilized by polyethyleneimine (PEI), and graphene stabilized by polyvinylpyrrolidone (PVP), from water using the layer-by-layer (LbL) assembly technique. This unique combination of carbon nanomaterials exhibits an electrical conductivity of 300 S cm−1 and a relatively stable power factor of 190 μW m−1 K−2 at room temperature.