Crystal Orientation and Grain Size: Do They Determine Optoelectronic Properties of MAPbI(3) Perovskite?
Autor: | Sandy Sanchez, Eline M. Hutter, Michael Saliba, Bruno Ehrler, Loreta A. Muscarella, Christian D. Dieleman, Tom J. Savenije, Anders Hagfeldt |
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Předmět: |
Diffraction
Letter Photoluminescence Materials science Infrared Annealing (metallurgy) FOS: Physical sciences Applied Physics (physics.app-ph) 02 engineering and technology Electron 010402 general chemistry 01 natural sciences ddc:530 General Materials Science Physical and Theoretical Chemistry boundaries Condensed Matter - Materials Science business.industry Materials Science (cond-mat.mtrl-sci) Physics - Applied Physics 021001 nanoscience & nanotechnology Grain size surface-defects recombination 0104 chemical sciences lead halide perovskites solar-cells thin-films Optoelectronics Charge carrier heterogeneity 0210 nano-technology business performance Electron backscatter diffraction |
Zdroj: | The Journal of Physical Chemistry Letters The journal of physical chemistry letters 10(20), 6010-6018 (2019). doi:10.1021/acs.jpclett.9b02757 The Journal of Physical Chemistry Letters, 10(20) |
ISSN: | 1948-7185 |
Popis: | It is thought that growing large, oriented grains of perovskite can lead to more efficient devices. We study MAPbI3 films fabricated via Flash Infrared Annealing (FIRA) consisting of highly oriented, large grains. Domains observed in the SEM are often misidentified with crystallographic grains, but SEM images don't provide diffraction information. We measure the grain size, crystal structure and grain orientation using Electron Back-Scattered Diffraction (EBSD) and we study how these affect the optoelectronic properties as characterized by local photoluminescence (PL) and time-resolved microwave conductivity measurements (TRMC). We find a spherulitic growth yielding large (tens of micron), highly oriented grains along the (112) and (400) planes in contrast to randomly oriented, smaller (400 nm) grains observed in films fabricated via conventional antisolvent (AS) dripping. We observe a local enhancement and shift of the photoluminescence emission at different regions of the FIRA clusters, but these can be explained with a combination of light-outcoupling and self-absorption. We observe no effect of crystal orientation on the optoelectronic properties. Additionally, despite a substantial difference in grain size between our FIRA sample and a conventional AS sample, we find similar photoluminescence and charge carrier mobilities and lifetime for the two films. These findings show that the optoelectronic quality is not necessarily related to the orientation and size of crystalline domains in perovskite films indicating that fabrication requirements may be more relaxed for perovskites. |
Databáze: | OpenAIRE |
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