Strain Engineering in Halide Perovskites

Despite the well-known implications in the field of III-V semiconductors, lattice strain in halide perovskite materials has been largely overlooked until recently. Here, we review the effect of lattice strain on the structural, chemical, and optoelectronic properties of metal halide perovskites to understand how strain engineering can be applied to improve device performance. We start by arguing that perovskites, like any other semiconducting material, are not immune to the negative effects of mismanaged strain. We analyze the origin- and detrimental consequences-of lattice strain in perovskite crystals and heterostructures. We then discuss how strain management addresses the polymorphism issue of some of the most desirable perovskite compositions, and how it prevents the harmful migration of ions in perovskites. We conclude by offering our perspective on the unexplored potential of strain engineering and argue that its controlled management can lead to untapped territories, including perovskite large-area single-crystalline thin films and electrically pumped lasers.