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Ultrafast Imaging of Carrier Transport across Grain Boundaries in Hybrid Perovskite Thin Films
- Source :
- ACS Energy Letters. 3:1402-1408
- Publication Year :
- 2018
- Publisher :
- American Chemical Society (ACS), 2018.
-
Abstract
- For optoelectronic devices based on polycrystalline semiconducting thin films, carrier transport across grain boundaries is an important process in defining efficiency. Here we employ transient absorption microscopy (TAM) to directly measure carrier transport within and across the boundaries in hybrid organic–inorganic perovskite thin films for solar cell applications with 50 nm spatial precision and 300 fs temporal resolution. By selectively imaging sub-bandgap states, our results show that lateral carrier transport is slowed down by these states at the grain boundaries. However, the long carrier lifetimes allow for efficient transport across the grain boundaries. The carrier diffusion constant is reduced by about a factor of 2 for micron-sized grain samples by the grain boundaries. For grain sizes on the order of ∼200 nm, carrier transport over multiple grains has been observed within a time window of 5 ns. These observations explain both the shortened photoluminescence lifetimes at the boundaries as we...
- Subjects :
- Photoluminescence
Materials science
Renewable Energy, Sustainability and the Environment
business.industry
Energy Engineering and Power Technology
02 engineering and technology
010402 general chemistry
021001 nanoscience & nanotechnology
01 natural sciences
Fick's laws of diffusion
0104 chemical sciences
law.invention
Fuel Technology
Chemistry (miscellaneous)
law
Temporal resolution
Solar cell
Materials Chemistry
Optoelectronics
Grain boundary
Crystallite
Thin film
0210 nano-technology
business
Perovskite (structure)
Subjects
Details
- ISSN :
- 23808195
- Volume :
- 3
- Database :
- OpenAIRE
- Journal :
- ACS Energy Letters
- Accession number :
- edsair.doi...........a53e3b18ba8a26a43e9f1ab0b9497ae1