Herein, we present the precise stoichiometric control of methlyammonium lead iodide perovskite thin-films using high vacuum dual-source vapor-phase deposition. We found that UV/Vis absorption and emission spectra were inadequate for assessing precisely the perovskite composition. Alternatively, inductively coupled plasma mass spectrometry (ICP-MS) is used to give precise, reproducible, quantitative measurements of the I/Pb ratio without systematic errors that often result from varying device thicknesses and morphologies. This controlled deposition method enables better understanding of the evaporation and deposition processes; methylammonium iodide evaporation appears omnidirectional, controlled using the chamber pressure and incorporated in the film through interaction with the unidirectionally evaporated PbI2. Furthermore, these thin-films were incorporated into solar cell device architectures with the best photovoltaic performance and reproducibility obtained for devices made with stoichiometric perovskite active layers. Additionally, and particularly pertinent to the field of perovskite photovoltaics, we found that the I-V hysteresis was unaffected by varying the film stoichiometry.
|Original language||English (US)|
|Number of pages||6|
|State||Published - 2015|
Bibliographical noteKAUST Repository Item: Exported on 2021-11-05
Acknowledged KAUST grant number(s): KUS-C1-015-21
Acknowledgements: The authors would like to thank Dr. Peng Gao for providing the MAI powder. N. T. thanks the King Abdullah University of Science and Technology (KAUST, Award No KUS-C1-015-21) for supporting his research. J. T. thanks the European Research Council for an Advanced Research Grant (ARG 247404) funded under the Mesolight project.
This publication acknowledges KAUST support, but has no KAUST affiliated authors.
ASJC Scopus subject areas
- Environmental Chemistry
- Materials Science(all)
- Chemical Engineering(all)