Temperature Dependence of the Urbach Energy in Lead Iodide Perovskites

Authors

Martin Ledinský, Tereza Schönfeldová, Jakub Holovský, Erkan Aydin, Zdeňka Hájková, Lucie Landová, Neda Neyková, Antonín Fejfar, Stefaan De Wolf

Laboratory / Department
Department of Thin Films and Nanostructures
Citation
https://doi.org/10.1021/acs.jpclett.9b00138
DOI
10.1021/acs.jpclett.9b00138
Year
2019

For photovoltaic and light-emitting materials, detailed information about their optical absorption spectra is essential. Here, we studied the temperature dependence of such spectra for methylammonium lead iodide (CH3NH3PbI3), with attention to its sub-band gap absorption edge (Urbach energy). Based on these data, we first find clear evidence for the universality of the correlation between the Urbach energy and open-circuit voltage losses of solar cells. Second, we find that for CH3NH3PbI3 the temperature-independent part of the Urbach energy is 3.8 ± 0.7 meV, which is smaller than that of best semiconducting materials underlining the remarkable optoelectronic properties of perovskites.

Comparison of static (temperature-independent) part of the Urbach energy of different semiconducting materials.
Comparison of static (temperature-independent) part of the Urbach energy of different semiconducting materials.

Cooperating institutions:

  • King Abdullah University of Science and Technology (KAUST), KAUST Solar Center (KSC), Thuwal, 23955-6900, Saudi Arabia (Stefaan De Wolf, Erkan Aydin)
  • Centre for Advanced Photovoltaics, Faculty of Electrical Engineering, Czech Technical University in Prague, 166 27 Prague, Czech Republic (Jakub Holovský, Lucie Landová)