On the origin of near-IR luminescence in Bi-doped materials (II) Subvalent monocation Bi^+ and cluster Bi_5 ^3+ luminescence in AlCl_3/ZnCl_2/BiCl_3 chloride glass

Abstract

Broadband NIR photoluminescence (from 1000 to 2500 nm) was observed from partially reduced AlCl₃/ZnCl₂/BiCl₃ glass, containing subvalent bismuth species. The luminescence consists of three bands, assigned to Bi⁺ , Bi₂⁴⁺, and Bi₅³⁺ ions. The physical and optical characteristics of these centers and possible contribution to NIR luminescence from bismuth-doped oxide glasses are discussed.

Optical and electronic properties of bismuth-implanted glasses

“…Bismuth-doped glasses can give rise to photoluminescence (PL) at wavelengths ranging from 400 nm [1] to 2500 nm [2], under variation of the pump wavelength and composition of the host glass. A wide variety of traditional glass hosts containing Bi have been investigated to date, mainly silicates [3][4][5] and germanates [6][7][8], but also phosphates [9], borates [10], chalcogenides [11,12] and chlorides [2].…”

“…A wide variety of traditional glass hosts containing Bi have been investigated to date, mainly silicates [3][4][5] and germanates [6][7][8], but also phosphates [9], borates [10], chalcogenides [11,12] and chlorides [2]. The origin of the infrared emission from Bi-doped glasses remains controversial, with convincing arguments being made for a variety of different emission centers, including Bi + [10], Bi 5+ [13,14], Bi metal clusters [8], point defects [15] and negatively charged Bi2 dimers [16,17].…”

Laser-assisted production of Bi-doped silica glasses

“…Bi þ and various clusters [27,28]), however it seems to be a hard challenge to prove their nature unambiguously. Although Fujimoto considers Bi 5 þ as luminescent active center [23], the formation of reduced valence states is more likely.…”

Influence of monovalent Bi+ doping on real composition, point defects, and photoluminescence in TlCdCl3 and TlCdI3 single crystals

“…The presence of bismuth in the form of isomorphous impurity in the position of cations having the formal charge 1+ (K, Rb, Cs, Tl) was only assumed based on the close ionic radii of Bi + and these cations [12]. It is isomorphism and synthesis conditions that formed the basis for correlating the spectral bands with Bi + ions [13][14][15][16][17][18]. However, neither confirmation of isomorphous substitution of the abovementioned components, nor consideration of any other possible Bi + locations in the crystal structures of Bi + -containing compounds with different compositions can be found in the literature.…”