Spectral and energy transfer in Bi3+–Ren+ (n = 2, 3, 4) co-doped phosphors: extended optical applications

Abstract

Bismuth with [Xe]4f¹⁴5d¹⁰6s²6p³ electronic configuration is considered as ‘a wonder metal’ due to its diverse oxidation states and multi-type electronic structures. This review article summarizes the spectral properties of phosphors doped with Bi³⁺ or co-doped with Bi³⁺–Reⁿ⁺ (n = 2, 3, 4), and highlights the critical role of Bi³⁺ in spectral modification. The energy transfer processes are discussed in detail, including (1) Bi³⁺ and metal-to-metal charge, (2) Bi³⁺ and tetravalent cation, (3) Bi³⁺ and trivalent cation, (4) Bi³⁺ and divalent cation, and (5) Bi³⁺ and two kinds of rare earth ions. The most important results obtained in each case are summarized, and the emerging challenges and future development of Bi³⁺-doped phosphors are discussed. We introduce a method for spectral modification based on the energy transfer between Bi³⁺ and other cations, with the perspective of development and application in the fields of phosphors, telecommunication, optical temperature sensing, biomedicine, and lasers.