An overview of the pressure- and strain-induced changes in the structural and optoelectronic properties of organometal halide perovskites

Spacer-Dependent and Pressure-Tuned Structures and Optoelectronic Properties of 2D Hybrid Halide Perovskites

“…The mechanical compression of perovskites can result in modification of the Pb–X bond lengths and angles in the inorganic lattice. The subsequent change in orbital overlap results in modification of the observed optoelectronic properties. − The effects of high pressure on 3D HOIPs, such as MAPbI 3 and FAPbI 3 , have been studied extensively. − More recently, high-pressure studies have been conducted on 2D lead-halide-based HOIPs, mostly focused on those with BA (butylammonium), PMA (phenyl methylammonium), or PEA (phenyl ethylammonium) spacer cations. − However, the effects of different spacer cations on the pressure-tuned optoelectronic properties are still not well understood. For example, the PMA and PEA spacer cations differ only by a CH 2 group, yet the high-pressure behaviors of (PMA) 2 PbI 4 and (PEA) 2 PbI 4 are drastically different.…”

Near‐infrared Piezochromic Materials at High Pressure

“…Developing PCMs has brought a different idea to this molecular design. The action of an external force can finely regulate the conformation and aggregation state of the molecules to achieve the purpose of regulating their luminescence peaks [8a,9a,15a] . In the initial state, the emission wavelengths of PCMs is in the visible light or NIR regions.…”

“…Xue′s group [9a] in 2016, An′s group [22] in 2018, and Tian's group [9c] in 2021 have presented the mechanochromic properties of organic phosphorescent molecules, organic/metal–organic compounds, and aggregation‐induced emission materials under different forces (including hydrostatic pressure), respectively, and systematically introduced changes in the luminescence of these materials after external stimuli. Moreover, in 2021 and 2022, Xu′s [9a] and Yang's [15a] groups, based on piezochromic behavior under hydrostatic pressure, have reviewed the evolution of photophysical properties and molecular behaviors of organic crystals and organometal halide perovskite materials under compression procedures, respectively. However, this study introduces the suppression piezochromic behaviors of different types of organic compounds under hydrostatic pressure.…”