Influence of the introduction of MoO3 in the cathode buffer layer on the behaviour of layered organic solar cells.
La revue : Indian Journal of Pure and Applied Physics
Domaine : physique
Mots Clés : Interfaces, organic compounds, oxides, vacuum deposition, ageing, electrical properties.
Auteur : K. El Assad Zemallach Ouari, Z. El Jouad, K. Benchouk, B. Kouskoussa, L. Cattin, M. Makha, A. Khelil, M. Morsli, M. Addou, J.C. Bernède.
Issn : Eissn : vol : 52, Num : , pp : 829-838
Date de publication : 2014-12-01
Résume : The behaviour of small-molecule organic solar cells based on coper-phthalocyanine/fullerene with different cathode buffer layer is investigated as a function of air exposure duration. We present the study of the effect of MoO3 on the properties of photovoltaic solar cells (OPVCs) when it is introduced in the cathode buffer layer (CBL). Photovoltaic performances were measured as a function of time of air exposure. During the first days of air exposure the efficiency of the OPVCs with MoO3 in their CBL increases significantly, while it decreases immediately after air exposure in the case of reference OPVCs, i.e. without MoO3 in the CBL. Nevertheless, the lifetime of the OPVCs with MoO3 in their CBL is around 60 days, while it
is only 10 days in the case of reference OPVCs. The initial increase of the OPVC with MoO3 in their CBL is attributed to the slow decrease of the work function of MoO3 due to progressive contamination. Then, the progressive degradation of the OPVCs efficiency is due water vapour and oxygen contamination of the organic layers. The use of a double CBL, Alq3/MoO3, allows to interrupt the growth of pinholes, defects and increases the path of permeating gas. Also it can prevent the contamination of the organic layer by Al. All this results in significant increase of the lifetime of the OPVCs
Indium free and flexible organic solar cells
La revue : Technology Letters
Domaine : physique
Mots Clés : Organic solar cells, Indium free, Flexibility, Electrical modelling.
Auteur : K. El Assad Zemallach Ouari, B. Kouskoussa, M. Makha, K. Benchouk, A. Khelil
Issn : 2348-8131 Eissn : vol : 2, Num : 3, pp : 5-11
Date de publication : 2015-07-01
Résume : The energy conversion efficiency of indium free flexible organic solar cells based on simple planar CuPc/C60 heterojunction is studied as a function of the anode free properties. The free indium anode consists in a MoO3/Ag/MoO3 multilayer structure. It is shown that the efficiency of the cells is optimized when the Ag film thickness is increased from 11nm to 17 nm. Moreover the best efficiency are achieved when a double anode buffer layer, Au/CuI is introduced between the MoO3/Ag/MoO3 electrode and the CuPc organic layer. Such behaviours are interpreted with the help of a equivalent electrical circuit of the cells. It is shown that, when deposited onto very thin flexible plastic substrate the properties of the MoO3/Ag/MoO3 electrodes are degraded during the realisation of the cell, which justifies the need of thicker Ag film and of the ultra tin Au film.
Structural properties of ternary buffer films based upon CuAlTe2
La revue : JIPMA
Domaine : physique
Mots Clés : Auteur : K. Benchouk; K. Zamallach; A. Khelil; J.C. Bernede
Issn : Eissn : vol : 13, Num : , pp : 01-04
Date de publication : 2010-01-01
Résume : Thin films of CuAlTe2 were elaborated by a sequential deposition of three elements
Cu; Al and Te under secondary vacuum on glass slides followed by an annealing of 1/2 hour in
an open tube within argon atmosphere. The X-rays diffraction diagram depicts a (112)
preferential orientation and the presence of low intensities peaks characterizing the
chalcopyrite structure. This shows that the majority of crystallites are directed towards the
(112) direction with an orientation factor having an approximate value of 70 %. The height of
the crystallites has been assessed using a scanning electron microscope and found to be larger