Study the Important Parameters Affecting Performances of P3HT: PCBM Organic Solar Cells

Abstract

Aims: Organic solar cells were realized and characterized. The structure of the device is Glass/ Transparent conducting oxide/ poly(3,4-ethylenedioxythiophene)-poly(styrene sulfonate)/ poly(3-hexylthiophene): : [6,6]-phenyl-C61-buytyric acid methyl ester/ Aluminum (Glass/ TCO/ Pedot:Pss/P3HT:PCBM/ Al). Where P3HT: PCBM is used as active layer. The J(V) characteristics and the parameters of the cells as function of concentration of the blend of the active layer, the thickness of the active layer and the type of substrate are given. Study Design: Theoretical study of the performances of organic solar cells is given. Followed by an experimental study. The cells were realized and characterized. Place and Duration of Study: Laboratory of Advanced Technologies of Genie Electrics (LATAGE) Faculty of Electrical and Computer Engineering Mouloud MAMMERI University (UMMTO), BP 17 RP 15000, Tizi-Ouzou, Algeria. Methodology: We discuss general mechanisms leading to generation and transport of charge carriers and parameters which govern the behavior of organic solar cells. The absorption spectra of P3HT: PCBM is measured using SAFAS 200 instrument for different temperatures. Solar cells were realized and characterized as function of different parameters: transparent electrodes, concentration of the active layer and thermal annealing. The current density characteristic results for the cells realized were compared for two substrates (indium tin oxide (ITO) and Fluor doped tin oxide (FTO)) and the concentration effect of the blend is studied. The decay of performances of these devices in the time is due to the degradation mechanisms which are a result of diffusion of H₂O and O₂ species through the organic layers. Results: The current density characteristic depends on various parameters, the type of the substrates, the concentration of the blend, thickness of active layer and thermal annealing. Conclusion: Our study shows that the performances of the organic solar cells depend on different parameters. In order to improve the performances of the cells, optimization of the concentration and thickness and the use of transparent electrodes with high transmittance and high conductivity must be used.