Bulk v nano-crystalline methyl ammonium lead bromide: structural origin for the high exciton binding energy in the nano-crystalline material

DOI

Organometal halide perovskite nanoparticles are brightly luminescent, due to their large exciton-binding energies. Extensive X-ray characterization studies, using synchrotron X-rays, imply that the high binding energy cannot be rationalized solely on the basis of quantum confinement. We find evidence that subtle strain-induced structural changes are behind the high binding energy in nanocrystalline (NC) materials. However, X-ray methods are not sensitive to the organic part of the NC materials. In order to establish the complete correlation between the structure and the electronic properties, we need to zoom in specifically on the organic cation, which is known to be a key player influencing both the short-range and the long-range ordering. Acquiring this structural missing link is the goal of the present proposal using NC and their bulk counterparts to probe the long-range order of the inorganic octahedral and organic units. Probing the organic cation order will give insight into the interplay with the halide framework, which influences electronic structure, and ferroelectricity implied by EXAFS, which can account for the different charge carrier dynamics of two samples.

Identifier
DOI https://doi.org/10.5291/ILL-DATA.5-24-575
Metadata Access https://data.ill.fr/openaire/oai?verb=GetRecord&metadataPrefix=oai_datacite&identifier=10.5291/ILL-DATA.5-24-575
Provenance
Creator Chen, Junsheng; Zheng, Kaibo; Henry, Paul; Canton, Sophie; Hansen, Thomas; Pullerits, Tönu
Publisher Institut Laue-Langevin
Publication Year 2017
Rights OpenAccess; info:eu-repo/semantics/openAccess
OpenAccess true
Representation
Resource Type Dataset
Size 173 MB
Version 1
Discipline Particles, Nuclei and Fields