Bidirectional Halide Ion Exchange in Paired Lead Halide Perovskite Films with Thermal Activation

Article

Abstract

MAPbBr3 and MAPbI3 films cast onto glass slides and physically paired together undergo halide exchange to form mixed halide films. The change in halide composition in these two ∼130 nm thick films occurs concurrently with Br− diffusing toward the MAPbI3 film and I− diffusing toward the MAPbBr3 film. The diffusion of these halide species, which is tracked through changes in the absorption, offers a direct measurement of thermally activated halide diffusion in perovskite films. The increase in the rate constant of halide diffusion with increasing temperature (from 8.3 × 10−6 s−1 at 23 °C to 3.7 × 10−4 s−1 at 140 °C) follows an Arrhenius relationship with activation energy of 51 kJ/mol. The thermally activated halide exchange shows the challenges of employing layers of different metal halide perovskites in stable tandem solar cells.

Attributes

Attribute NameValues
Creator
  • R. Scheidt

  • B. Seger

  • P. Kamat

Journal or Work Title
  • ACS Energy Letter

Volume
  • 4

First Page
  • 1961

Last Page
  • 1969

ISSN
  • 2380-8195

Publication Date
  • 2019-07

Subject
  • Titan TEM

Publisher
  • American Chemical Society

Date Created
  • 2019-08-08

Language
  • English

Departments and Units
Record Visibility and Access Public
Content License
  • All rights reserved

Digital Object Identifier

doi:10.1021/acsenergylett.9b01280

This DOI is the best way to cite this article.