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Rousset, France

Peres L.,Aix - Marseille University | Bou A.,CROSSLUX | Barakel D.,Aix - Marseille University | Torchio Ph.,Aix - Marseille University
RSC Advances | Year: 2016

A ZnS|Ag|TiO2 (ZAT) multilayer architecture is proposed as an alternative to symmetric TiO2|Ag|TiO2 (TAT) electrodes. The TAT electrodes were proved to be among the best ITO-free transparent conductive electrodes. It is demonstrated that choosing ZnS instead of TiO2 as a substrate for Ag allows better optical and electrical performances. The complex refractive indices of both dielectric materials are determined by spectroscopic ellipsometry and implemented into a transfer matrix algorithm to optimize the optical transmittance of ZAT and TAT multilayers in the visible part of the spectrum. It is shown that both types of electrodes are equivalent in terms of optical behavior. Manufactured electrodes with symmetric 40 nm dielectric thicknesses are then fabricated on glass substrates by e-beam evaporation and the effect of the silver layer thickness on performances is studied. It is found that ZAT multilayer performances are systematically better, and on a broader transmittance range, when the Ag layer is very thin than TAT stacks. A state of the art 90.23% maximum transmittance is reached at λ = 460 nm for a ZnS(36 nm) |Ag(12.7 nm)|TiO2(37 nm) multilayer, with a sheet resistance RS of 5 Ω Sq-1. Over 80% transmittance is achieved in the [380-855] nm wavelength range for a ZnS(36 nm)|Ag(7 nm)|TiO2(40 nm) multilayer, with a RS of 11.3 Ω Sq-1. Scanning electron microscopy (SEM) reveals continuous silver films grown on ZnS as opposed to those grown on TiO2, thus justifying the better performances of the ZAT. © 2016 The Royal Society of Chemistry. Source

A method for producing a thin-film photovoltaic device (

Ayachi B.,CNRS Institute of Electronics, Microelectronics and Nanotechnology | Aviles T.,CROSSLUX | Vilcot J.-P.,CNRS Institute of Electronics, Microelectronics and Nanotechnology | Sion C.,CNRS Institute of Electronics, Microelectronics and Nanotechnology | Sion C.,Ecole Centrale Lille
Applied Surface Science | Year: 2016

Room temperature deposited aluminium-doped zinc oxide thin films on glass substrate, using pulsed-DC magnetron sputtering, have shown high optical transmittance and low electrical resistivity with high uniformity of its spatial distribution after they were exposed to a rapid thermal annealing process at 400 °C under N2H2 atmosphere. It is particularly interesting to note that such an annealing process of AZO thin films for only 30 s was sufficient, on one hand to improve their optical transmittance from 73% to 86%, on the other hand to both decrease their resistivity from 1.7 × 10-3 Ω cm to 5.1 × 10-4 Ω cm and achieve the highest uniformity spatial distribution. To understand the mechanisms behind such improvements of the optoelectronic properties, electrical, optical, structural and morphological changes as a function of annealing time have been investigated by using hall measurement, UV-visible spectrometry, X-ray diffraction and scanning electron microscope imaging, respectively. © 2016 Elsevier B.V. All rights reserved. Source

Bou A.,Aix - Marseille University | Torchio P.,Aix - Marseille University | Barakel D.,Aix - Marseille University | Thoulon P.-Y.,CROSSLUX | Ricci M.,CROSSLUX
Thin Solid Films | Year: 2016

Indium Tin Oxide (ITO) is the most commonly used transparent and conductive electrode (TCE) for organic solar cells and other optoelectronic components. One possible alternative to ITO is to use an Oxide|Metal|Oxide multilayer TCE. A numerical and experimental study resulting in an optically and electrically optimized TiOx |Ag|TiOx (TAT) TCE is presented. Single Ag and TiOx layers as well as Ag|TiOx and TiOx |Ag bilayers are first investigated. Both oxide thicknesses are then adjusted to give to the TAT trilayer electrode its best transparency in the considered absorption spectral band. The metal layer thickness controls both electrical and optical (mainly in the near-infrared spectral range) properties of the electrode. Electrodes with such TiOx (37 nm)|Ag (13 nm)|TiOx (42 nm) design have been produced, which present excellent balance between transparency - 91% of solar energy in the target spectral band that passes through the multilayer - and sheet resistance - average value around 4.7 Ω/□. © 2015 Elsevier B.V. Source

Bou A.,Aix - Marseille University | Torchio P.,Aix - Marseille University | Vedraine S.,Aix - Marseille University | Barakel D.,Aix - Marseille University | And 4 more authors.
Solar Energy Materials and Solar Cells | Year: 2014

A numerical process is developed on a Transfer-Matrix Method (TMM) to calculate the optical properties of multilayers involved in thin film solar cells. Using the bulk complex refractive indices in a considered spectral range for each material allows us to calculate the transmittance of the whole structure and the intrinsic absorption inside the sole active layer. An optical optimization of oxide|metal|oxide trilayer electrode in the air and with a (poly-3-hexylthiophene):[6,6]-phenyl-C61-butyric acid methyl ester (P3HT:PCBM) bulk heterojunction based organic solar cell is performed. The ZnO|Ag|ZnO structure is specifically studied in order to avoid the use of indium in such photovoltaic components. © 2014 Elsevier B.V. Source

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