Luminescence properties of Ni2+ in CsCdBr3

Abstract

Optical properties of Ni2+ ions substituted in CsCdBr3 crystal have been investigated from 9 to 300 K. Strictly forbidden transitions for spin, electric, or magnetic dipole selection rules in a purely cubic environment are observed in the absorption spectrum. The interpretation of these spectroscopic features is performed on the basis of trigonally distorted symmetry of the Ni*+ site and by taking into account the first-order spin-orbit interaction. In this framework, the cubic spin-orbit sublevels undergo further splitting due to the trigonal field. The energy-level calculation performed in this model agrees fairly well with experimental values. The trigonal-field parameter is estimated to be-780 cm-1. A better accuracy in the trigonal sublevels energies is obtained by taking into account the emission data. Four emission bands were observed in the 0.9-2.6 pm spectral range. These are ascribed to radiative deexcitation from the jTp excited state to the lower excited states ST2, 3T1, 1E for the higher-energy transitions, and from the ST2 level to the ground state for the lower-energy emission. The temperature dependence of the lifetimes was fitted by the Mott law and in the Struck and Fonger model. On the basis of the latter model, decay processes are proposed.

Yb3+-sensitized visibleNi2+photon upconversion in codopedGarcı́a-Revilla1, Gerner2, Güdel3 et al. 2005Phys. Rev. B14060View full textAdd to dashboardCite

“…9͑b͔͒ and CsMgBr 3 : 4.9% Ni 2+ , 0.6% Yb 3+ , respectively ͑see Tables I and II͒ single doped compounds. 39,44 For the scenario shown in Fig. 10͑a͒, one would predict a lifetime of the UC emission around 2.7 and 6.8 s for the Cd 2+ and Mg 2+ host lattice, respectively, or even smaller due to the additional deactivation channels, such as the energy transfer from Ni 2+ to Yb 3+ .…”

“…Since then, numerous reports devoted to the investigation of the optical spectroscopic properties of Ni 2+ as a dopant ion in different host lattices appeared. [34][35][36][37][38][39][40] In the past few years Ni 2+ UC has been intensively studied in different singly doped fluoride, 41 chloride, 15,17,42,43 and bromide 44,45 host lattices. This UC process ͑ascribed to a GSA-ESA mechanism͒ involves two spin forbidden transitions, which limits its efficiency.…”

Dual Luminescence and Excited-State Dynamics in Ti2+ Doped NaCl

“…In this sense Ni 2+ and Ti 2+ show unique photophysical properties among the octahedrally coordinated d ions. Of these two ions, Ni 2+ is clearly the spectroscopically more thoroughly studied: Higher excited-state emission has been observed in Ni 2+ doped oxides, fluorides, chlorides, and bromides . By contrast, there is only one material in which dual luminescence from Ti 2+ has so far been reported, namely, Ti 2+ :MgCl 2 …”

“…Of these two ions, Ni 2+ is clearly the spectroscopically more thoroughly studied: Higher excited-state emission has been observed in Ni 2+ doped oxides, 6 fluorides, 7 chlorides, 8 and bromides. 9 By contrast, there is only one material in which dual luminescence from Ti 2+ has so far been reported, namely, Ti 2+ :MgCl 2 . 10 The MgCl 2 lattice is a rather exceptional host for Ti 2+ , since the latter experiences a very strong ligand field in this matrix.…”

Optical spectroscopy of theNi2+-doped layer perovskitesRb2Wenger1, Valiente2, Güdel3 2001Phys. Rev. B20030View full textAdd to dashboardCite

“…Later, continuouswave laser operation of Ni 2ϩ :MgO was achieved at 80 K. 3 In 1970, it was recognized that at cryogenic temperatures Ni 2ϩ exhibits multiple emissions in MgO, 4 and it has since been shown to do so in a variety of materials including fluorides, 5,6 chlorides, 7 and bromides. 8 Thus, among octahedrally coordinated transition-metal ions, Ni 2ϩ represents one of the few exceptions to Kasha's rule, 9 which states that luminescence is to be expected, if at all, only from the lowest excited state. As such the Ni 2ϩ ion has become subject of various photon-up-conversion studies, in which its first excited state serves as a metastable energy storage reservoir, from where up-conversion to a higher excited emitting state can occur, thus leading to short-wavelength emission after long-wavelength irradiation.…”