@article{ZeiskeSandbergZarrabietal.2022,
  author    = {Zeiske, Stefan and Sandberg, Oskar J. and Zarrabi, Nasim and Wolff, Christian Michael and Raoufi, Meysam and Pe{\~n}a-Camargo, Francisco and Gutierrez-Partida, Emilio and Meredith, Paul and Stolterfoht, Martin and Armin, Ardalan},
  title     = {Static disorder in lead halide perovskites},
  series = {The journal of physical chemistry letters},
  volume    = {13},
  journal   = {The journal of physical chemistry letters},
  number    = {31},
  publisher = {American Chemical Society},
  address   = {Washington},
  issn      = {1948-7185},
  doi       = {10.1021/acs.jpclett.2c01652},
  pages     = {7280 -- 7285},
  year      = {2022},
  abstract  = {In crystalline and amorphous semiconductors, the temperature-dependent Urbach energy can be determined from the inverse slope of the logarithm of the absorption spectrum and reflects the static and dynamic energetic disorder. Using recent advances in the sensitivity of photocurrent spectroscopy methods, we elucidate the temperature-dependent Urbach energy in lead halide perovskites containing different numbers of cation components. We find Urbach energies at room temperature to be 13.0 +/- 1.0, 13.2 +/- 1.0, and 13.5 +/- 1.0 meV for single, double, and triple cation perovskite. Static, temperature-independent contributions to the Urbach energy are found to be as low as 5.1 ?+/- 0.5, 4.7 +/- 0.3, and 3.3 +/- 0.9 meV for the same systems. Our results suggest that, at a low temperature, the dominant static disorder in perovskites is derived from zero-point phonon energy rather than structural disorder. This is unusual for solution-processed semiconductors but broadens the potential application of perovskites further to quantum electronics and devices.},
  language  = {en}
}
@article{MatternPudellLaskinetal.2021,
  author    = {Mattern, M. and Pudell, Jan-Etienne and Laskin, G. and von Reppert, A. and Bargheer, Matias},
  title     = {Analysis of the temperature- and fluence-dependent magnetic stress in laser-excited SrRuO3},
  series = {Structural Dynamics},
  journal   = {Structural Dynamics},
  issn      = {2329-7778},
  doi       = {10.1063/4.0000072},
  pages     = {9},
  year      = {2021},
  abstract  = {We use ultrafast x-ray diffraction to investigate the effect of expansive phononic and contractive magnetic stress driving the picosecond strain response of a metallic perovskite SrRuO3 thin film upon femtosecond laser excitation. We exemplify how the anisotropic bulk equilibrium thermal expansion can be used to predict the response of the thin film to ultrafast deposition of energy. It is key to consider that the laterally homogeneous laser excitation changes the strain response compared to the near-equilibrium thermal expansion because the balanced in-plane stresses suppress the Poisson stress on the picosecond timescale. We find a very large negative Gr{\"u}neisen constant describing the large contractive stress imposed by a small amount of energy in the spin system. The temperature and fluence dependence of the strain response for a double-pulse excitation scheme demonstrates the saturation of the magnetic stress in the high-fluence regime.},
  language  = {en}
}