Phase Stability and Diffusion in Lateral Heterostructures of Methyl Ammonium Lead Halide Perovskites.

TitlePhase Stability and Diffusion in Lateral Heterostructures of Methyl Ammonium Lead Halide Perovskites.
Publication TypeJournal Article
Year of Publication2019
AuthorsKennard RM, Dahlman CJ, Nakayama H, DeCrescent RA, Schuller JA, Seshadri R, Mukherjee K, Chabinyc ML
JournalACS Appl Mater Interfaces
Volume11
Issue28
Pagination25313-25321
Date Published2019 Jul 17
ISSN1944-8252
Abstract

Mixed halide hybrid organic-inorganic perovskites have band gaps that span the visible spectrum making them candidates for optoelectronic devices. Transport of the halide atoms in methyl ammonium lead iodide (MAPbI) and its alloys with bromine has been observed in both dark and under illumination. While halide transport upon application of electric fields has received much attention, less is known regarding bromide and iodide interdiffusion down concentration gradients. This work provides an upper bound on the bromide-iodide interdiffusion coefficient in thin films of MAPb(BrI) using a diffusion couples of lateral heterostructures. The upper bound of was extracted from changes in the interface profiles of the heterostructures upon exposure to heat. The stability of thoroughly heated interfacial profiles suggests that the miscibility gap extends to higher temperatures and to a higher fractional composition of bromine than predicted by theory. The results of this work provide guidance for compositions of thermally stable heterostructures of hybrid halide perovskites.

DOI10.1021/acsami.9b06069
Alternate JournalACS Appl Mater Interfaces
PubMed ID31268293