The Renaissance of Functional Hybrid Transition-Metal Halides

Abstract

Metrics & More Article RecommendationsCONSPECTUS: There is an extensive history of research on both inorganic and hybrid metal halides, with the latter being first reported in the 1960s. Although work on hybrid systems has progressed steadily over the last 60 years, it has enjoyed a major renaissance during the last 5 years. This has arisen as a consequence of the 2009 discovery of the outstanding optoelectronic properties of hybrid lead halides, such as (MA)PbI 3 (MA = methylammonium), and the recognition that there are many opportunities for equally exciting discoveries with compounds of the transition metals. Some of the early work on hybrid transition-metal halides put more emphasis on crystal structures but less on properties. In the modern era, we aim to grasp both the structure and properties, with a new twist. In this Account, we shall explore the recent developments in hybrid transition-metal halides with a focus on work in four main areas: magnetism, photoluminescence, semiconductivity, and spintronics. Our work on magnetism centers on the Ru-based hybrid halides, where the structural types are diversely composed of vacancy-ordered double perovskite, as well as chain-like one-dimensional structures and layered double perovskite (LDP) when paired with a (1+) metal. We explore their magnetic properties and find that their spin−orbit coupling (SOC) behavior can be tuned through changing the A cation and the halide. In the luminescence section, we focus on our recent works on hybrid tetrahedral Mn(II) bromides and Cu(I) and Ag(I) iodides. We correlated our newly discovered 0D A m MnBr 4 (A = organic cation, m = 1 or 2) compounds with previous reports, and generated a trend where the photoluminescence quantum yield (PLQY) increases with larger Mn−Mn distances. The flexible organic cation becomes the most important tool here to tune the structure−PLQY relations. Cu(I) and Ag(I) iodides coordinated with iodides and organic ligands produce new crystal structures with intense PL. For the semiconducting properties, we explore the Pt-based vacancy-ordered double perovskite and hybrid bismuth and indium-based LDPs to show the structural evolution with different choices for the organic cation, the metal and the halide; these have a strong influence on the optical properties. The LDPs specifically exhibit high structure tunability, with a wide range of (1+) and (3+) metal choices, and are exempt from some of the limitations of 3D double perovskite. In the last section, we introduce the recent progress on hybrid transition-metal-based ferroelectrics and spintronic materials. We successfully demonstrate the utilization of chiral Cu(II) chlorides for circularly polarized light (CPL) detection, showing the high anisotropy of the photoresponsivity. We also highlight the work that the authors have contributed in these areas and suggest several exciting opportunities for future developments.

Achieving Near‐unity Photoluminescence Quantum Yields in Organic‐Inorganic Hybrid Antimony (III) Chlorides with the [SbCl5] Geometry

“…Hybrid organic–inorganic metal halides show great potentials for a variety of optoelectronic applications such as solar cells [1, 2] and light‐emitting diodes [3–5] . They are highly flexible with organic counterparts, [6] inorganic metals, [7] and halide components [8] . For example, hybrid lead halide perovskite materials have demonstrated highly diverse structural, optical, and electronic properties with the templating effects of organic cations and halide variations [9–11] .…”

Chiral 2D Cu(I) Halide Frameworks

“…Advanced multifunctional materials that integrate multiple properties in a single crystalline material have attracted a tremendous amount of research interest. − In recent years, hybrid organic–inorganic metal halides have been considered promising functional materials because of their structural diversity and extraordinary photophysical properties. − Due to the tunable compositions and flexible crystal structures of hybrid organic–inorganic metal halides, chiral moieties can be rationally introduced into the system as ligands or templating cations, enabling the construction of multifunctional materials. − Chirality transfer from organic modules to inorganic moieties can be effectively realized not only through the formation of chemical bonds but also through spatial interactions. , Intrinsic chirality introduced in metal hybrid materials will generally break the symmetry, leading to novel chirality-related optoelectronic properties, such as circular dichroism (CD), , circularly polarized luminescence (CPL), second harmonic generation (SHG), pyroelectricity, piezoelectricity, and ferroelectricity . In addition, due to the interaction between chirality and spin, the introduction of chirality into organic–inorganic hybrid metal halides with a strong spin orbit coupling system (Pb and I) also has broad application prospects in spintronics. , …”

Upconversion and multiexciton generation in organic Mn(ii) complex boost the quantum yield to > 100%

“…8 Along with the intriguing optical properties, Mn-based 0D hybrid materials are an important class of light-emitting materials that can replace toxic lead-based halide perovskites. [35][36][37][38][39][40][41][42][43][44][45][46] Recent reports have proven the possibility of fabricating lightemitting devices with Mn(II) complexes. Chen et al 47 reported solution-processed green LEDs using an ionic tetrabromide Mn(II) complex and reported an EQE of 9.6% and a brightness of 2339 cd m À2 , whereas Huang et al 48 fabricated vacuum processed LEDs using neutral tetrahedral Mn(II) complexes and reported a high current efficiency (CE) and power efficiency (PE) of 35.47 cd A À1 and 34.35 lm W À1 and with a maximum luminescence of 1412 cd m À2 .…”