Quantifying Anionic Diffusion in 2D Halide Perovskite Lateral Heterostructures
Abstract
Anionic diffusion strongly impacts the stability of halide perovskite materials, but it is still not well understood. Here, a quantitative investigation of in‐plane thermally driven anionic inter‐diffusion in a series of novel 2D and quasi‐2D halide perovskites lateral heterostructures is reported. The calculated diffusion coefficients (D) reveal the inhibition of Br–I inter‐diffusion with bulky π‐conjugated organic cations compared with short‐chain aliphatic organic cations. Furthermore, halide diffusion is found to be faster in quasi‐2D (n > 1) than 2D perovskites (n = 1). The increment becomes less apparent as the “n” number increases, akin to the quantum confinement effect observed for band gaps. These trends are rationalized by molecular dynamics simulations of free energy barriers for halide diffusion that reveal mechanisms for suppressing diffusion. This work provides important fundamental insights on the anionic migration and diffusion process in halide perovskite materials.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Oct 15, 2021
- Source ID
- 10.1002/adma.202105183
Entities
People
- Akriti
- Alan J. Pistone
- Blake P Finkenauer
- Brett Savoie
- Enzheng Shi
- Ke Ma
- Letian Dou
- Shuchen Zhang
- Yao Gao
- Zih‐Yu Lin
Organizations
- Air Force Office of Scientific Research
- Office of Basic Energy Sciences
- Office of Naval Research
- Purdue University
- United States Department of Energy
- Westlake University