Realization of tin oxide like anode for the manufacture of the organic solar cells

The transparent oxides such as SnO2, In2O3 and ZnO continue to arouse a private interest for their various applications. The objective of the various studies being to carry out the layers which are simultaneously most transparent and most conducting possible. Thus in the field of the solar spectrum, the transmission of the layers must be higher than 80% and their conductivity exceeding 103 (Ohm.cm)-1. Their transparency which is related to the value of their forbidden band must be higher than 3.7 e V. Their electric properties as for them depend on the composition of the layers and a possible doping. In this work, one characterized layers of SnO2 deposited by chemical pulverization, one carried out measurements by, electronic scan microscopy, diffraction of x-rays and also of the optical measurements and electronic. It results from it that the layers are conducting and transparent in the visible one but they are relatively rough, following its characterizations, one carried out organic photovoltaic cells using these layers of SnO2 and also of the commercial ITO like anode in these components. More particularly one was interested in the influence of the presence of a fine layer of gold between the anode and organic material

Highlighting the possibility of parallel mechanism in planar ternary photovoltaic cells

International audienc

Highlighting the possibility of parallel mechanism in planar ternary photovoltaic cells

Ternary and binary planar heterojunctions (PHJs) have been realized and characterized. The outer layers of the active organic layers are pentathiophene (5T) and fullerene (C60), while the intercalated layer is AlPcCl. The binary, 5T/C60, 5T/AlPcCl and ternary 5T/AlPcCl/C60 PHJs were characterized by J-V and EQE measurements. The morphology of the organic layers was studied by scanning electron microscopy and atomic force microscopy, while the band structure of 5T was estimated by cyclic voltammetry. The study shows that it is possible to overcome the difficulties linked to the need for the good band matching of the three successive organic layers by using as a first electron donor layer, a layer whose morphology allows the ternary structure to behave as it was two diodes in parallel. Actually, due to this specific morphology the intercalated layer is discontinuous, which allows achieving parallel mechanism in planar ternary photovoltaic cells. This parallel mechanism in the 5T/AlPcCl/C60 organic photovoltaic cells (OPVCs) allows achieving efficiency of 1.25%, which represents a 65 % increase by comparison with the best binary 5T/C60 OPVC. It means that the morphology of the 5T layer, with its many protrusions and holes, allows ternary OPVCs to behave like parallel-linkage diodes. This behaviour allows the ternary OPVCs to achieve efficiencies higher than those obtained with the binary 5T/C60 OPVCs