  Metal halide perovskites have recently emerged as promising materials for the
next generation of optoelectronic devices owing to their remarkable intrinsic
properties. In the growth of perovskite crystals, the substrates are essential
and play a vital role. Herein, substrate engineering in the growth of
perovskite crystals have been reviewed. Particularly, various modified
strategies and corresponding mechanism based on the substrate engineering
applied to the optimization of thickness, nucleation and growth rate are
highlighted. Then the alterable adhesion to substrates will also be discussed.
Furthermore, applying the structural coherence of epitaxial crystals with
substrate, scalable perovskite single-crystalline thin films have been obtained
and can be transferred onto arbitrary substrates. Substrate engineering also
can stabilize the desired perovskite phases by modulating the strain between
crystals and substrates. Finally, several key challenges and related solutions
in the growth of perovskite crystals based on substrate engineering are
proposed. This review aims to guide the future of substrate engineering in
perovskite crystals for various optoelectronic applications.
