Abstract
Growing large, oriented grains of perovskite often leads to efficient devices, but it is unclear if properties of the grains are responsible for the efficiency. Domains observed in SEM are commonly misidentified with crystallographic grains, but SEM images do not provide diffraction information. We study methylammoinium lead iodide (MAPbI3) films fabricated via flash infrared annealing (FIRA) and the conventional antisolvent (AS) method by measuring grain size and orientation using electron back-scattered diffraction (EBSD) and studying how these affect optoelectronic properties such as local photoluminescence (PL), charge carrier lifetimes, and mobilities. We observe a local enhancement and shift of the PL emission at different regions of the FIRA clusters, but we observe no effect of crystal orientation on the optoelectronic properties. Additionally, despite substantial differences in grain size between the two systems, we find similar optoelectronic properties. These findings show that optoelectronic quality is not necessarily related to the orientation and size of crystalline domains.
| Original language | English |
|---|---|
| Pages (from-to) | 6010-6018 |
| Number of pages | 9 |
| Journal | Journal of Physical Chemistry Letters |
| Volume | 10 |
| Issue number | 20 |
| DOIs | |
| Publication status | Published - 17 Oct 2019 |
| Externally published | Yes |
Funding
The authors thank Erik C. Garnett for providing feedback on the paper and Andries Lof for technical support during the EBSD measurements. This work is part of the research program of The Netherlands Organization for Scientific Research (NWO). S.S. and M.S. thank the Adolphe Merkle Institute at the University of Fribourg, Switzerland, for past support.