Effects of Moisture-Based Grain Boundary Passivation on Cell Performance and Ionic Migration in Organic-Inorganic Halide Perovskite Solar Cells.
Md Nadim Ferdous HoqueRui HeJuliusz WarzywodaZhaoyang FanPublished in: ACS applied materials & interfaces (2018)
Because of the polycrystalline nature, grain boundaries (GBs) in hybrid perovskite thin films play critical roles in determining the charge collection efficiency of perovskite solar cells (PSCs), material stability, and in particular the ion migration, considering their relatively soft ionic bonds with low formation energy. Different GB passivation methods are being studied, and introducing PbI2-rich phase at GBs in methylammonium lead iodide (MAPbI3) has been found to be useful. In this study, combining macroscale measurements with tip-based microscopic probing that includes scanning Kelvin probe microscopy for surface potential mapping and conductive atomic force microscopy for charge transport mapping, we revealed the effects of PbI2-rich phase at GBs, which was introduced in moisture-assisted synthesis of MAPbI3 thin films. It was found that PbI2 passivation of GBs could change the surface potential and charge carrier screening and significantly retard current conduction at the GB while enhancing conduction through the grain interior. Inhibition of ion migration at GBs, as well as enhanced PSC device performance, is reported.
Keyphrases
- perovskite solar cells
- high resolution
- atomic force microscopy
- solar cells
- single molecule
- high speed
- single cell
- ionic liquid
- solid state
- high density
- high throughput
- room temperature
- human health
- mass spectrometry
- optical coherence tomography
- stem cells
- molecular dynamics simulations
- mesenchymal stem cells
- climate change
- high efficiency