Defect quantification in metal halide perovskites: the solid-state electrochemical alternative
AffiliationDepartment of Chemical and Environmental Engineering, The University of Arizona
Department of Chemistry and Biochemistry, The University of Arizona
Department of Materials Science and Engineering, The University of Arizona
MetadataShow full item record
PublisherRoyal Society of Chemistry
CitationDe Keersmaecker, M., Armstrong, N. R., & Ratcliff, E. L. (2021). Defect quantification in metal halide perovskites: The solid-state electrochemical alternative. Energy and Environmental Science, 14(9), 4840–4846.
JournalEnergy & Environmental Science
RightsCopyright © 2021 De Keersmaecker, Armstrong, & Ratcliff.
Collection InformationThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at firstname.lastname@example.org.
AbstractElectrochemical methodologies are routinely used to determine energetics and defect density in semiconductor materials under operando conditions. For metal halide perovskites, electrochemical methods are restricted to a limited group of non-solvent electrolytes. This challenge is circumvented via a ”peel and stick” solid electrolyte that can contain redox active species, is transparent to visible and X-ray photons for simultaneous characterizations, and can be removed for quantification of near-surface composition and energetics using photoelectron spectroscopies. Defects are qualified for both near-stoichiometric and over-stoichiometric MAPbI3 films using controlled hole and electron injection, afforded through potential modulation with respect to a calibrated internal reference. Inclusion of mid-gap redox probes (ferrocene) allows for probing density of states, whereby electron transfer reversibility is shown to be dependent upon the number of ionized defects at the perovskite's band edges. A detailed Coulombic analysis is provided for determination of defect energetics and densities, with a near-stoichiometric film exhibiting a defect density of ∼2 × 1017 cm−3 at 0.1 eV above the valence band. We predict that this easily implemented three-electrode platform will be translatable to operando characterization of a range of semiconductor materials, including thin film perovskites, (in)organic semiconductors, quantum dots, and device stacks, where the removable solid electrolyte functions as the “top contact”.
Note12 month embargo; first published: 24 July 2021
VersionFinal accepted manuscript
SponsorsThis work was supported by the Office of Naval Research under Award Number N00014-20-1-2440. NRA gratefully acknowledges partial salary support from the Office of Research, Innovation, and Impact (RII) at the University of Arizona.