Study of halide gradient formation via solution-solid halide exchange in crystalline CH₃NH₃PbBr₃ thin films

Authors

Behnaz Akbari, University of Nebraska-LincolnFollow

First Advisor

Yinsheng Guo

Date of this Version

Summer 7-31-2021

Document Type

Article

Citation

Behnaz Akbari, Yinsheng Guo., Study of halide gradient formation via solution-solid halide exchange in crystalline CH3NH3Br3 thin films, in Chemistry. July, 2021, University of Nebraska.

Comments

A THESIS Presented to the Faculty of The Graduate College at the University of Nebraska In Partial Fulfillment of the Requirements For the Degree of Master of Science, Major: Chemistry, Under the Supervision of Professor Yinsheng Guo. Lincoln, Nebraska: July, 2021

Copyright © 2021 Behnaz Akbari

Abstract

In this thesis, attempts have been made to understand halide exchange and mass transport inside the solid lattice of Lead Halide Perovskites (LHPs). We aim for the transformation of MAPbBr₃ using ionic solutions including 1-Butyl-3-methylimidazolium iodide (BMIMI), and 1-Butyl-3-methylimidazolium chloride (BMIMCl) as halide ion sources to observe the halide diffusion across the thin film sample and to have LHPs with a gradient of mixed halides (MAPbBr_3-x (I/Cl)_x, 0 ≤ x ≤ 3). Successfully, MAPbBr₃ single-crystalline thin film was fabricated with different configurations. Surface analysis of the LHPs, elemental composition, halide diffusion, roughness, and size of grains in our thin film was examined using a scanning electron microscope equipped with Energy-dispersive X-ray Spectroscopy (SEM-EDX), photoluminescence (PL), and Dektak-XT stylus surface profiling system.

Advisor: Yinsheng Guo