Molecular spectroscopy of hybrid organic-inorganic perovskites and related compounds

Hybrid organic-inorganic perovskites (HOIPs) constitute unique coordination polymers with a huge potential of transforming modern materials chemistry due to their wide applications, mainly in electronics, optoelectronics and photovoltaics. Yearly, thousands of works on HOIPs are published in various fields of science, technology and industry. Many of these studies are devoted to structural and structure-related properties. Molecular spectroscopy methods (optical and broadband dielectric spectroscopy, IR, Raman, EPR, NMR) are often used to understand their magnetic, optical and luminescent properties; energy conversion; basic molecular dynamics; hydrogen bond-associated guest moleculeframework interactions; stability; flexibility; mechanisms of temperature- and pressure induced phase transitions; and other more sophisticated physical phenomena, such as polar properties, ferroelectricity, multiferroicity, etc. The goal of this review is to create a comprehensive and versatile phase-related guide for researchers working in the field of HOIPs using a wide range of molecular spectroscopy techniques. This review presents a systematical description of very recent achievements obtained using modern molecular spectroscopy methods. It also summarizes the current state of knowledge on HOIPs, including metal formates, hypophosphites, azides, cyanides, dicyanamides, and halides templated by protonated amines and phosphines that adopt a perovskite architecture. (C) 2021 Elsevier B.V. All rights reserved.