کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
81045 | 49417 | 2007 | 7 صفحه PDF | دانلود رایگان |
Films of MEH-PPV and PPDI blends with weight ratio 1:2 have been prepared by spin-coating and annealing between 0 and 60 min at 95 °C. The films were characterized by absorption spectroscopy and atomic force microscopy (AFM). The main emphasis has been on the photon conversion efficiency in the photovoltaic cells as a function of excitation wavelength and applied voltage/electric field. Site selective excitation at wavelengths at which either non-aggregated bulk PPDI or dimers/aggregates of PPDI absorb prove that (i) the rate-limiting process for power conversion is the field-assisted escape of optically generated geminate electron–hole pairs from their mutual coulombic potential and (ii) the photogeneration yield depends on the donor–acceptor topology. A significant difference of the yield has been noted when alkoxy-pendent groups in MEH-PPV are replaced by phenyl-alkoxy groups.
Journal: Solar Energy Materials and Solar Cells - Volume 91, Issue 19, 23 November 2007, Pages 1842–1848