Enhanced UVB emission and analysis of chemical states of Ca5(PO4)3OH:Gd3+,Pr3+ phosphor prepared by co-precipitation

UV Emission of Gd3+ in the Presence of Cu2+: Towards Luminescence Quenching through Quantum Cutting?

“…Thus, it seems that the presence of Gd 3 + promotes, to some extent, the manifestation of luminescent copper. A similar result was recently reported by Tong et al [25] for SnO 2 for gadolinium doping promoting lower oxidation states in transition-metal ions is not well understood at present. However, although the data in Figure 3 suggests that some Cu + is present in the GdCu0.2-0.6 glasses, the comparable intensities of the PL bands indicate that there is an equivalent amount present in each of the glasses.…”

“…6 I J transitions). [2,3] A relatively weak and broad emission band is observed towards the visible region for the GdCu0.2-0.6 glasses. This is likely due to luminescence from traces of monovalent copper (e.g.…”

“…[1][2][3] Hence, approaches to maximize the efficiency of UV-type B light (280-320 nm) emission, which is suitable for such applications, are currently under investigation. For instance, co-doping with a sensitizer, [2,4] variation of host band structure, [4] and control over the atmosphere during the synthesis of the materials [5] have been considered as important parameters. Materials systems containing gadolinium have also been investigated for the development of luminescent materials through quantumcutting processes.…”

“…6 I J transitions around 275 nm). [2,3] Thus, an energy match between these two transitions could potentially lead to a Gd 3 + !Cu 2 + electronic excitation transfer, which could reduce emission from the 6 P 7/2 metastable state in Gd 3 + . Furthermore, it may be postulated that if a two-photon quantumcutting process [6,15] takes place from the 6 P 7/2 state, which emits at around 310 nm, energies that are relevant to Cu 2 + absorption in the visible region (d-d transitions) could be reached, and the resonance condition could be fulfilled.…”

Enhanced UV emission of Gd3+ in glass by Ag+ co-doping

“…Activating optical materials with Gd 3 þ ions is nowadays attractive for creating suitable sources of ultraviolet (UV) light to be integrated in phototherapy lamps for the treatment of skin diseases [1][2][3][4][5]. Accordingly, approaches are currently sought for enhancing the UV type B (UVB) light (280-320 nm) emission appropriate for the biomedical applications.…”