@article{ZhangHosseiniGunderetal.2019,
  author    = {Zhang, Shanshan and Hosseini, Seyed Mehrdad and Gunder, Rene and Petsiuk, Andrei and Caprioglio, Pietro and Wolff, Christian Michael and Shoaee, Safa and Meredith, Paul and Schorr, Susan and Unold, Thomas and Burn, Paul L. and Neher, Dieter and Stolterfoht, Martin},
  title     = {The Role of Bulk and Interface Recombination in High-Efficiency Low-Dimensional Perovskite Solar Cells},
  series = {Advanced materials},
  volume    = {31},
  journal   = {Advanced materials},
  number    = {30},
  publisher = {Wiley-VCH},
  address   = {Weinheim},
  issn      = {0935-9648},
  doi       = {10.1002/adma.201901090},
  pages     = {11},
  year      = {2019},
  abstract  = {2D Ruddlesden-Popper perovskite (RPP) solar cells have excellent environmental stability. However, the power conversion efficiency (PCE) of RPP cells remains inferior to 3D perovskite-based cells. Herein, 2D (CH3(CH2)(3)NH3)(2)(CH3NH3)(n-1)PbnI3n+1 perovskite cells with different numbers of [PbI6](4-) sheets (n = 2-4) are analyzed. Photoluminescence quantum yield (PLQY) measurements show that nonradiative open-circuit voltage (V-OC) losses outweigh radiative losses in materials with n > 2. The n = 3 and n = 4 films exhibit a higher PLQY than the standard 3D methylammonium lead iodide perovskite although this is accompanied by increased interfacial recombination at the top perovskite/C-60 interface. This tradeoff results in a similar PLQY in all devices, including the n = 2 system where the perovskite bulk dominates the recombination properties of the cell. In most cases the quasi-Fermi level splitting matches the device V-OC within 20 meV, which indicates minimal recombination losses at the metal contacts. The results show that poor charge transport rather than exciton dissociation is the primary reason for the reduction in fill factor of the RPP devices. Optimized n = 4 RPP solar cells had PCEs of 13\% with significant potential for further improvements.},
  language  = {en}
}
@article{WarbyZuZeiskeetal.2022,
  author    = {Warby, Jonathan and Zu, Fengshuo and Zeiske, Stefan and Gutierrez-Partida, Emilio and Frohloff, Lennart and Kahmann, Simon and Frohna, Kyle and Mosconi, Edoardo and Radicchi, Eros and Lang, Felix and Shah, Sahil and Pena-Camargo, Francisco and Hempel, Hannes and Unold, Thomas and Koch, Norbert and Armin, Ardalan and De Angelis, Filippo and Stranks, Samuel D. and Neher, Dieter and Stolterfoht, Martin},
  title     = {Understanding performance limiting interfacial recombination in pin Perovskite solar cells},
  series = {Advanced energy materials},
  volume    = {12},
  journal   = {Advanced energy materials},
  number    = {12},
  publisher = {Wiley-VCH},
  address   = {Weinheim},
  issn      = {1614-6832},
  doi       = {10.1002/aenm.202103567},
  pages     = {10},
  year      = {2022},
  abstract  = {Perovskite semiconductors are an attractive option to overcome the limitations of established silicon based photovoltaic (PV) technologies due to their exceptional opto-electronic properties and their successful integration into multijunction cells. However, the performance of single- and multijunction cells is largely limited by significant nonradiative recombination at the perovskite/organic electron transport layer junctions. In this work, the cause of interfacial recombination at the perovskite/C-60 interface is revealed via a combination of photoluminescence, photoelectron spectroscopy, and first-principle numerical simulations. It is found that the most significant contribution to the total C-60-induced recombination loss occurs within the first monolayer of C-60, rather than in the bulk of C-60 or at the perovskite surface. The experiments show that the C-60 molecules act as deep trap states when in direct contact with the perovskite. It is further demonstrated that by reducing the surface coverage of C-60, the radiative efficiency of the bare perovskite layer can be retained. The findings of this work pave the way toward overcoming one of the most critical remaining performance losses in perovskite solar cells.},
  language  = {en}
}