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Updated: Jan 29, 2026

Inkjet Printing All Inorganic Halide Perovskite Inks for Photovoltaic Applications
Published on: January 22, 2019
Homogenized halides and alkali cation segregation in alloyed organic-inorganic perovskites
Juan-Pablo Correa-Baena1,2, Yanqi Luo3,4, Thomas M Brenner3,4
1Massachusetts Institute of Technology, Cambridge, MA 02139, USA. jpcorrea@gatech.edu buonassisi@mit.edu dfenning@eng.ucsd.edu.
Abstract:
The role of the alkali metal cations in halide perovskite solar cells is not well understood. Using synchrotron-based nano-x-ray fluorescence and complementary measurements, we found that the halide distribution becomes homogenized upon addition of cesium iodide, either alone or with rubidium iodide, for substoichiometric, stoichiometric, and overstoichiometric preparations, where the lead halide is varied with respect to organic halide precursors. Halide homogenization coincides with long-lived charge carrier decays, spatially homogeneous carrier dynamics (as visualized by ultrafast microscopy), and improved photovoltaic device performance. We found that rubidium and potassium phase-segregate in highly concentrated clusters. Alkali metals are beneficial at low concentrations, where they homogenize the halide distribution, but at higher concentrations, they form recombination-active second-phase clusters.
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Alkyl Halides
Alkyl halides are halogen-substituted alkanes wherein one or more hydrogen atoms of an alkane is replaced by a halogen atom such as fluorine, chlorine, bromine, or iodine. The carbon atom in an alkyl halide is bonded to the halogen atom, which is sp3-hybridized and exhibits a tetrahedral shape.
Unlike alkyl halides, compounds in which a halogen atom is bonded to an sp2 -hybridized carbon atom of a carbon-carbon double bond (C=C) are called vinyl halides. Whereas aryl...

