Effect of Light Incidence Angle on Optical Absorption Characteristics of Bulk Heterojunction Organic Solar Cells

We have computationally analysed how the light incident angle influences the absorption characteristics of bulk heterojunction solar cells by the electro-magnetic field analysis method. The absorbed optical power in three different active layers was calculated by using the Poynting's theorem, resulting that it was significantly decreased under the incidence angle larger than 30 degrees by the optical interference. In addition, we understood that the absorptivity of lower band-gap active layers could be more affected by the incidence angle variation.