@article{ZuAmsalemEggeretal.2019,
  author    = {Zu, Fengshuo and Amsalem, Patrick and Egger, David A. and Wang, Rongbin and Wolff, Christian Michael and Fang, Honghua and Loi, Maria Antonietta and Neher, Dieter and Kronik, Leeor and Duhm, Steffen and Koch, Norbert},
  title     = {Constructing the Electronic Structure of CH3NH3PbI3 and CH3NH3PbBr3 Perovskite Thin Films from Single-Crystal Band Structure Measurements},
  series = {The journal of physical chemistry letters},
  volume    = {10},
  journal   = {The journal of physical chemistry letters},
  number    = {3},
  publisher = {American Chemical Society},
  address   = {Washington},
  issn      = {1948-7185},
  doi       = {10.1021/acs.jpclett.8b03728},
  pages     = {601 -- 609},
  year      = {2019},
  abstract  = {Photovoltaic cells based on halide perovskites, possessing remarkably high power conversion efficiencies have been reported. To push the development of such devices further, a comprehensive and reliable understanding of their electronic properties is essential but presently not available. To provide a solid foundation for understanding the electronic properties of polycrystalline thin films, we employ single-crystal band structure data from angle-resolved photoemission measurements. For two prototypical perovskites (CH3NH3PbBr3 and CH3NH3PbI3), we reveal the band dispersion in two high-symmetry directions and identify the global valence band maxima. With these benchmark data, we construct "standard" photoemission spectra from polycrystalline thin film samples and resolve challenges discussed in the literature for determining the valence band onset with high reliability. Within the framework laid out here, the consistency of relating the energy level alignment in perovskite-based photovoltaic and optoelectronic devices with their functional parameters is substantially enhanced.},
  language  = {en}
}
@article{SalzmannHeimelDuhmetal.2012,
  author    = {Salzmann, Ingo and Heimel, Georg and Duhm, Steffen and Oehzelt, Martin and Pingel, Patrick and George, Benjamin M. and Schnegg, Alexander and Lips, Klaus and Blum, Ralf-Peter and Vollmer, Antje and Koch, Norbert},
  title     = {Intermolecular hybridization governs molecular electrical doping},
  series = {Physical review letters},
  volume    = {108},
  journal   = {Physical review letters},
  number    = {3},
  publisher = {American Physical Society},
  address   = {College Park},
  issn      = {0031-9007},
  doi       = {10.1103/PhysRevLett.108.035502},
  pages     = {5},
  year      = {2012},
  abstract  = {Current models for molecular electrical doping of organic semiconductors are found to be at odds with other well-established concepts in that field, like polaron formation. Addressing these inconsistencies for prototypical systems, we present experimental and theoretical evidence for intermolecular hybridization of organic semiconductor and dopant frontier molecular orbitals. Common doping-related observations are attributed to this phenomenon, and controlling the degree of hybridization emerges as a strategy for overcoming the present limitations in the yield of doping-induced charge carriers.},
  language  = {en}
}