Rare-Earth Doping in Nanostructured Inorganic Materials

Abstract

Impurity doping is a promising method to impart new properties to various materials. Due to their unique optical, magnetic, and electrical properties, rare-earth ions have been extensively explored as active dopants in inorganic crystal lattices since the 18th century. Rare-earth doping can alter the crystallographic phase, morphology, and size, leading to tunable optical responses of doped nanomaterials. Moreover, rare-earth doping can control the ultimate electronic and catalytic performance of doped nanomaterials in a tunable and scalable manner, enabling significant improvements in energy harvesting and conversion. A better understanding of the critical role of rare-earth doping is a prerequisite for the development of an extensive repertoire of functional nanomaterials for practical applications. In this review, we highlight recent advances in rare-earth doping in inorganic nanomaterials and the associated applications in many fields. This review covers the key criteria for rare-earth doping, including basic electronic structures, lattice environments, and doping strategies, as well as fundamental design principles that enhance the electrical, optical, catalytic, and magnetic properties of the material. We also discuss future research directions and challenges in controlling rare-earth doping for new applications.

Structural, optical spectroscopy and energy transfer features of Tb3+-activated (Y, Gd)F3 nanophosphors for UV-based LEDs

“…[1][2][3] In particular, rare earth (RE) doped inorganic nanophosphors have been the focus of great interest due to the wide emission bands of RE 3+ ions in the ultraviolet to infrared region of the electromagnetic spectrum and their ability to produce highly narrow, bright, sensitive and selective luminescence signals, which are important for many optical applications. [4][5][6] Among the various groups of inorganic host matrices, fluoride lattices show many interesting features, providing high coordination numbers for dopant RE 3+ ions, as well as the low phonon energy associated with the lattices being mainly responsible for minimal nonradiative losses. Moreover, in this class, yttrium fluoride (YF 3 ) is one of the best host matrices owing to its very low phonon energy (350-400 cm À1 ), wide band gap (410 eV) and, most importantly, its Y 3+ sites can be easily substituted by RE 3+ ions without any charge compensation.…”

Rare‐Earth Single‐Atom Catalysts: A New Frontier in Photo/Electrocatalysis

“…The variety of 4f states having different occupancies in RE‐based materials results in interesting narrowband optical properties, especially because of the facilitated intra‐atomic 4f–4f transitions. [ 89 ]…”

“…The variety of 4f states having different occupancies in REbased materials results in interesting narrowband optical properties, especially because of the facilitated intra-atomic 4f-4f transitions. [89] As a result, when RE elements are used as dopants in photoactive materials, the synergism between the 4f states and surface vacancies can reduce the band gap (E g ) on visible-light irradiation because the 4f states act as a quasi-VB below the CB, thus enhancing photocatalytic activity. [90] Thus, RE SACs can act as active sites in photocatalysts because of their more exposed valence 4f states.…”

Controlling X-ray-activated persistent luminescence for emerging applications

“…Adapted, with permission, from [63]. [53][54][55], this discovery immediately stimulated tremendous scientific interest. Subsequently, the X-PersL behaviors of NaYF 4 :Tb 3+ and NaLuF 4 :Pr 3+ were elaborately discussed by Yang and colleagues and Capobianco and colleagues in 2020, respectively [56,57].…”