Illumination angle and layer thickness influence on the photo current generation in organic solar cells: A combined simulative and experimental study

• Main Authors: Jan Mescher, Adrian Mertens, Amos Egel, Siegfried W. Kettlitz, Uli Lemmer, Alexander Colsmann
• Format: Article
• Language: English
• Published: AIP Publishing LLC 2015-07-01
• Series: AIP Advances
• Online Access: http://dx.doi.org/10.1063/1.4928074

In most future organic photovoltaic applications, such as fixed roof installations, facade or clothing integration, the solar cells will face the sun under varying angles. By a combined simulative and experimental study, we investigate the mutual interdependencies of the angle of light incidence, the absorber layer thickness and the photon harvesting efficiency within a typical organic photovoltaic device. For thin absorber layers, we find a steady decrease of the effective photocurrent towards increasing angles. For 90-140 nm thick absorber layers, however, we observe an effective photocurrent enhancement, exhibiting a maximum yield at angles of incidence of about 50°. Both effects mainly originate from the angle-dependent spatial broadening of the optical interference pattern inside the solar cell and a shift of the absorption maximum away from the metal electrode.