@article{AlbrechtSchaeferLangeetal.2012,
  author    = {Albrecht, Steve and Schaefer, Sebastian and Lange, Ilja and Yilmaz, Seyfullah and Dumsch, Ines and Allard, Sybille and Scherf, Ullrich and Hertwig, Andreas and Neher, Dieter},
  title     = {Light management in PCPDTBT:PC70BM solar cells: A comparison of standard and inverted device structures},
  series = {Organic electronics : physics, materials and applications},
  volume    = {13},
  journal   = {Organic electronics : physics, materials and applications},
  number    = {4},
  publisher = {Elsevier},
  address   = {Amsterdam},
  issn      = {1566-1199},
  doi       = {10.1016/j.orgel.2011.12.019},
  pages     = {615 -- 622},
  year      = {2012},
  abstract  = {We compare standard and inverted bulk heterojunction solar cells composed of PCPDTBT:PC70BM blends. Inverted devices comprising 100 nm thick active layers exhibited short circuit currents of 15 mA/cm(2), 10\% larger than in corresponding standard devices. Modeling of the optical field distribution in the different device stacks proved that this enhancement originates from an increased absorption of incident light in the active layer. Internal quantum efficiencies (IQEs) were obtained from the direct comparison of experimentally derived and modeled currents for different layer thicknesses, yielding IQEs of similar to 70\% for a layer thickness of 100 nm. Simulations predict a significant increase of the light harvesting efficiency upon increasing the layer thickness to 270 nm. However, a continuous deterioration of the photovoltaic properties with layer thickness was measured for both device architectures, attributed to incomplete charge extraction. On the other hand, our optical modeling suggests that inverted devices based on PCPDTBT should be able to deliver high power conversion efficiencies (PCEs) of more than 7\% provided that recombination losses can be reduced.},
  language  = {en}
}
@misc{LaquaiAndrienkoDeibeletal.2017,
  author    = {Laquai, Frederic and Andrienko, Denis and Deibel, Carsten and Neher, Dieter},
  title     = {Charge carrier generation, recombination, and extraction in polymer-fullerene bulk heterojunction organic solar cells},
  series = {Elementary processes in organic photovoltaics},
  volume    = {272},
  journal   = {Elementary processes in organic photovoltaics},
  publisher = {Springer},
  address   = {Berlin},
  isbn      = {978-3-319-28338-8},
  issn      = {0065-3195},
  doi       = {10.1007/978-3-319-28338-8_11},
  pages     = {267 -- 291},
  year      = {2017},
  abstract  = {In this chapter we review the basic principles of photocurrent generation in bulk heterojunction organic solar cells, discuss the loss channels limiting their efficiency, and present case studies of several polymer-fullerene blends. Using steady-state and transient, optical, and electrooptical techniques, we create a precise picture of the fundamental processes that ultimately govern solar cell efficiency.},
  language  = {en}
}