@article{TockhornSutterCruzBournazouetal.2022,
  author    = {Tockhorn, Philipp and Sutter, Johannes and Cruz Bournazou, Alexandros and Wagner, Philipp and J{\"a}ger, Klaus and Yoo, Danbi and Lang, Felix and Grischek, Max and Li, Bor and Li, Jinzhao and Shargaieva, Oleksandra and Unger, Eva and Al-Ashouri, Amran and K{\"o}hnen, Eike and Stolterfoht, Martin and Neher, Dieter and Schlatmann, Rutger and Rech, Bernd and Stannowski, Bernd and Albrecht, Steve and Becker, Christiane},
  title     = {Nano-optical designs for high-efficiency monolithic perovskite-silicon tandem solar cells},
  series = {Nature nanotechnology},
  volume    = {17},
  journal   = {Nature nanotechnology},
  number    = {11},
  publisher = {Nature Publishing Group},
  address   = {London [u.a.]},
  issn      = {1748-3387},
  doi       = {10.1038/s41565-022-01228-8},
  pages     = {1214 -- 1221},
  year      = {2022},
  abstract  = {Designing gentle sinusoidal nanotextures enables the realization of high-efficiency perovskite-silicon solar cells <br /> Perovskite-silicon tandem solar cells offer the possibility of overcoming the power conversion efficiency limit of conventional silicon solar cells. Various textured tandem devices have been presented aiming at improved optical performance, but optimizing film growth on surface-textured wafers remains challenging. Here we present perovskite-silicon tandem solar cells with periodic nanotextures that offer various advantages without compromising the material quality of solution-processed perovskite layers. We show a reduction in reflection losses in comparison to planar tandems, with the new devices being less sensitive to deviations from optimum layer thicknesses. The nanotextures also enable a greatly increased fabrication yield from 50\% to 95\%. Moreover, the open-circuit voltage is improved by 15 mV due to the enhanced optoelectronic properties of the perovskite top cell. Our optically advanced rear reflector with a dielectric buffer layer results in reduced parasitic absorption at near-infrared wavelengths. As a result, we demonstrate a certified power conversion efficiency of 29.80\%.},
  language  = {en}
}
@article{GrischekCaprioglioZhangetal.2022,
  author    = {Grischek, Max and Caprioglio, Pietro and Zhang, Jiahuan and Pena-Camargo, Francisco and Sveinbjornsson, Kari and Zu, Fengshuo and Menzel, Dorothee and Warby, Jonathan H. and Li, Jinzhao and Koch, Norbert and Unger, Eva and Korte, Lars and Neher, Dieter and Stolterfoht, Martin and Albrecht, Steve},
  title     = {Efficiency Potential and Voltage Loss of Inorganic CsPbI2Br Perovskite Solar Cells},
  series = {Solar RRL},
  volume    = {6},
  journal   = {Solar RRL},
  number    = {11},
  publisher = {Wiley-VCH},
  address   = {Weinheim},
  issn      = {2367-198X},
  doi       = {10.1002/solr.202200690},
  pages     = {12},
  year      = {2022},
  abstract  = {Inorganic perovskite solar cells show excellent thermal stability, but the reported power conversion efficiencies are still lower than for organic-inorganic perovskites. This is mainly caused by lower open-circuit voltages (V(OC)s). Herein, the reasons for the low V-OC in inorganic CsPbI2Br perovskite solar cells are investigated. Intensity-dependent photoluminescence measurements for different layer stacks reveal that n-i-p and p-i-n CsPbI2Br solar cells exhibit a strong mismatch between quasi-Fermi level splitting (QFLS) and V-OC. Specifically, the CsPbI2Br p-i-n perovskite solar cell has a QFLS-e center dot V-OC mismatch of 179 meV, compared with 11 meV for a reference cell with an organic-inorganic perovskite of similar bandgap. On the other hand, this study shows that the CsPbI2Br films with a bandgap of 1.9 eV have a very low defect density, resulting in an efficiency potential of 20.3\% with a MeO-2PACz hole-transporting layer and 20.8\% on compact TiO2. Using ultraviolet photoelectron spectroscopy measurements, energy level misalignment is identified as a possible reason for the QFLS-e center dot V-OC mismatch and strategies for overcoming this V-OC limitation are discussed. This work highlights the need to control the interfacial energetics in inorganic perovskite solar cells, but also gives promise for high efficiencies once this issue is resolved.},
  language  = {en}
}