Near‐Infrared Light Emitting Metal Halides: Materials, Mechanisms, and Applications

Abstract

Near‐Infrared (NIR) light emitting metal halides are emerging as a new generation of optical materials owing to their appealing features, which include low‐cost synthesis, solution processability and adjustable optical properties. NIR emitting perovskite‐based light‐emitting diodes (LEDs) have reached an external quantum efficiency (EQE) over 20% and a device stability of over 10,000 h. Such results have sparked an interest in exploring new NIR metal halide emitters. In this review, we summarize several different types of NIR‐emitting metal halides, including lead/tin bromide/iodide perovskites, lanthanide ions doped/based metal halides, double perovskites, low dimensional hybrid and Bi3+/Sb3+/Cr3+ doped metal halides, and assess their recent advancements. The characteristics and mechanisms of narrow‐band or broadband NIR luminescence in all these materials are discussed in detail. We also highlight the various applications of NIR‐emitting metal halides and provide an outlook for the field.This article is protected by copyright. All rights reserved

Bandgap Narrowing in Europium(II)-Based Bromide Hybrids toward Improved X-ray Scintillation and Imaging

“…Lanthanide halides show a great prospect in the optoelectronic field, , especially scintillation by virtue of the intrinsic heavy-element attribute. For instance, Lu 3+ and Tb 3+ have been successfully doped into all-inorganic halide materials to afford good X-ray scintillation property. , Although Eu 2+ is one of the lanthanide ions that exhibited impressive and excellent luminescence in phosphors owing to the 4f-5d transition, less attention has been paid in the scintillation fields.…”

“…4−9 Given the dilemma in the toxicity of lead halide perovskites and the relatively long lifetime of manganese halide hybrids, the exploration of the X-ray scintillators with brand-new B-site cations is in urgent demand. 10 Lanthanide halides show a great prospect in the optoelectronic field, 11,12 especially scintillation by virtue of the intrinsic heavy-element attribute. For instance, Lu 3+ and Tb 3+ have been successfully doped into all-inorganic halide materials to afford good X-ray scintillation property.…”

Temperature-dependent self-trapped models regulating energy transfer in rare earth double perovskites via 5s2 electron doping

“…It is widely recognized that doping with rare earth elements is an effective method for tuning luminescent color. 17–22 Rare earth ions typically exhibit a wide emission range from ultraviolet (UV) to infrared due to their rich (4f n ) electronic configurations, along with long PL lifetimes and excellent optical stability. 23–26 Xia's group reported on Bi 3+ :Cs 2 Ag(In 1− x Tb x )Cl 6 halide perovskites, 27 which modulated luminescence from green to orange.…”