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Witt, Christina ; Schötz, Konstantin ; Köhler, Anna ; Panzer, Fabian:
Understanding Method-Dependent Differences in Urbach Energies in Halide Perovskites.
In: The Journal of Physical Chemistry C.
Bd. 128
(2024)
Heft 15
.
- S. 6336-6345.
ISSN 1932-7455
DOI: https://doi.org/10.1021/acs.jpcc.3c07293
Abstract
The Urbach energy as a measure of energetic disorder is an important characteristic of semiconductors to evaluate their optoelectronic functionality. However, discrepancies occur in Urbach energy values EU determined via different measurement and analysis methods, whose origin of a profound understanding is still missing. To reliably analyze the origin of such discrepancies, we recorded quasi-simultaneously temperature-dependent absorption and photoluminescence (PL) spectra of halide perovskite (MAPbI3) thin-film and single-crystal samples. Performing profound Urbach analyses in an extended energy range down to 0.2 eV below the bandgap, we find energy-range-dependent exaggeration effects on Urbach energy values to be only present in the near bandgap region (∼0.02 eV below the bandgap), where non-Urbach absorption states start to contribute. Besides that, generally lower EU values and a lower temperature-dependence of EU are obtained from PL than from absorption, which originates from the sensitivity of PL for sites with lower energetic disorder and/or higher phonon energies in the excited-state geometry. Thus, our work is sensitized to proper interpretation and comparison of EU values and contributes to developing a more fundamental understanding of semiconductor materials.The Urbach energy as a measure of energetic disorder is an important characteristic of semiconductors to evaluate their optoelectronic functionality. However, discrepancies occur in Urbach energy values EU determined via different measurement and analysis methods, whose origin of a profound understanding is still missing. To reliably analyze the origin of such discrepancies, we recorded quasi-simultaneously temperature-dependent absorption and photoluminescence (PL) spectra of halide perovskite (MAPbI3) thin-film and single-crystal samples. Performing profound Urbach analyses in an extended energy range down to 0.2 eV below the bandgap, we find energy-range-dependent exaggeration effects on Urbach energy values to be only present in the near bandgap region (∼0.02 eV below the bandgap), where non-Urbach absorption states start to contribute. Besides that, generally lower EU values and a lower temperature-dependence of EU are obtained from PL than from absorption, which originates from the sensitivity of PL for sites with lower energetic disorder and/or higher phonon energies in the excited-state geometry. Thus, our work is sensitized to proper interpretation and comparison of EU values and contributes to developing a more fundamental understanding of semiconductor materials.
Weitere Angaben
| Publikationsform: | Artikel in einer Zeitschrift |
|---|---|
| Begutachteter Beitrag: | Ja |
| Institutionen der Universität: | Fakultäten > Fakultät für Mathematik, Physik und Informatik > Physikalisches Institut Fakultäten > Fakultät für Mathematik, Physik und Informatik > Physikalisches Institut > Lehrstuhl Experimentalphysik II - Optoelektronik weicher Materie Fakultäten > Fakultät für Mathematik, Physik und Informatik > Physikalisches Institut > Lehrstuhl Experimentalphysik II - Optoelektronik weicher Materie > Lehrstuhl Experimentalphysik II - Optoelektronik weicher Materie - Univ.-Prof. Dr. Anna Köhler Fakultäten Fakultäten > Fakultät für Mathematik, Physik und Informatik |
| Titel an der UBT entstanden: | Ja |
| Themengebiete aus DDC: | 500 Naturwissenschaften und Mathematik > 530 Physik |
| Eingestellt am: | 11 Apr 2024 07:19 |
| Letzte Änderung: | 12 Sep 2024 12:54 |
| URI: | https://eref.uni-bayreuth.de/id/eprint/89292 |