Heteroepitaxy of Large-Area, Monocrystalline Lead Halide Perovskite Films on Gallium Arsenide

TL;DR

This paper demonstrates the epitaxial growth of large-area, monocrystalline lead halide perovskite films on gallium arsenide substrates using a solution process, advancing scalable high-quality perovskite film fabrication.

Contribution

It introduces a novel two-step epitaxial method for growing monocrystalline MAPbBr3 films on GaAs with a lattice-matched PbS interface, enabling large-scale high-quality perovskite films.

Findings

Successful epitaxial growth of monocrystalline MAPbBr3 on GaAs

Identification of crystal orientations confirming monocrystallinity

Elucidation of a two-step growth process

Abstract

Lead halide perovskite materials have been emerging as promising candidates for high-performance optoelectronic devices. Significant efforts have sought to realize monocrystalline perovskite films at a large scale. Here, we epitaxially grow monocrystalline methylammonium lead tribromide (MAPbBr3) films on lattice-matched gallium arsenide (GaAs) substrates at a centimeter scale. In particular, a solution-processed lead(II) sulfide (PbS) layer provides a lattice-matched and chemical protective interface for the solid-gas reaction to form MAPbBr3 films on GaAs. Structure characterizations identify the crystal orientations in the trilayer MAPbBr3/PbS/GaAs epi-structure and confirm the monocrystalline nature of MAPbBr3 on PbS/GaAs. The dynamic evolution of surface morphologies during the growth indicates a two-step epitaxial process. These fundamental understandings and practical growth techniques offer a viable guideline to approach high-quality perovskite films for previously inaccessible applications.