The interest in perovskite-based solar cell absorber materials has skyrocketed in recent years due to the rapid rise in solar cell efficiency and the potential for cost reductions tied to solution-processed device fabrication. Due to complications associated with the presence of strong static and dynamic disorder in these organic-inorganic materials, the fundamental photophysical behavior of photo-excited charge carriers remains unclear. We apply four-wave mixing spectroscopy to study the charge carrier dynamics in CH₃NH₃PbI₃ thin films. Our experiments reveal two discrete optical transitions below the band gap of the semiconductor with binding energies of 13 meV and 29 meV, attributed to free and defect-bound excitons respectively.

Date Published: 23 February 2017
PDF: 6 pages
Proc. SPIE 10102, Ultrafast Phenomena and Nanophotonics XXI, 1010211 (23 February 2017); doi: 10.1117/12.2252709

Published in SPIE Proceedings Vol. 10102:
Ultrafast Phenomena and Nanophotonics XXI
Markus Betz; Abdulhakem Y. Elezzabi, Editor(s)