Influence of PEDOT:PSS layer on the performances of "bulk-heterojunction" photovoltaic cells based on MEH-PPV:PCBM(1:4) polymeric blends
Résumé
Photovoltaic cells having as active layer a mixture between poly[2-[2',5'-bis(2-ethyhexyloxy)phenyl]-1,4-phenylenevinylene]-co-[2-methoxy-5-(2'-ethylexyloxy)-1,4-phenylenevinylene] (MEH-PPV) regioregular polymer and [6,6]-phenyl C 61 butyric acid methyl ester (PCBM) fullerene derivative were prepared on ITO covered optical glass and plastic sheets, as substrates. The samples have the same architecture, the main difference between them being the presence or not of poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT:PSS). For all the prepared structures, the morphological, optical and electrical characterization was carried out, comparatively. The current-voltage (I-V) characteristics in monochromatic light and the action spectra of the prepared structures were recorded, at room temperature. The parameters characterizing photovoltaic cells (short-circuit current, open circuit voltage and fill factor) were calculated and compared for prepared structures with or without PEDOT:PSS "buffer" layer.