UVB‐emitting Gd³⁺‐activated M₂O₂S (where M = La, Y) for phototherapy lamp phosphors

Abstract

Gd(3+)-activated oxysulphide (M2O2S) may be used to study Photoluminescence (PL) properties with respect to phototherapy. Gd(3+)-activated phosphor materials are widely used for phototherapy lamps. The Gd(3+) ion gives characteristic Narrow-Band (NB) emissions, in particular in the ultraviolet (UV) light region, that are used to treat more than 50 types of skin diseases. In this paper, M2O2S oxysulphide doped with Gd(3+) was synthesized by the solid-state flux fusion method and its down conversion spectral properties were studied as a function of different Gd(3+) concentrations. The sample was characterized by X-ray Diffraction (XRD), Scanning Electron Microscope (SEM), Fourier Transform Infrared Spectroscopy (FT-IR), and PL and the crystal structure was also studied. The lanthanum oxysulphide (La2O2S)-activated Gd(3+) ion showed a sharp emission peak at 314 nm when excited at 275 nm excitation, whereas the yttrium oxysulphide (Y2O2S)-activated Gd(3+) ion showed a sharp emission at 316 nm when excited by 272 nm. The effect of concentration of the Gd(3+) ion on the luminescence properties of M2O2S:Gd(3+) phosphor was also studied. These phosphor materials activated with the Gd(3+) ion may be suitable for phototherapy lamps, which are used to treat many types of skin diseases such as psoriasis, vitiligo, or scleroderma.

Intense Photoluminescence Emission in Eu3+‐ and Dy3+‐ Doped Low‐Band Gap Perovskite Titanate, Na0.5Gd0.5TiO3

“…The diffuse reflectance spectrum of the parent phase is shown in Figure . The absorption band at around 272 nm corresponds to the 8 S 7/2 → 6 I 7/2 intra 4 f transition of Gd 3+ ,. From the absorption edge, the optical band gap obtained using the Kubelka‐Munk function is 3.41 eV.…”

Photoluminescence and electron paramagnetic resonance properties of a potential phototherapic agent: MMgF4:Gd3+ (M = Ba, Sr) sub‐microphosphors

“…In Gd 3 + ions, 4f shell is half filled and is shielded by completely filled 5 s and 5p shells. Among the lanthanides, Gd 3 + ions have the largest energy gap between the ground and excited states, which is 32 000 cm ‐1 ; hence, its excitation and emission spectra lie within the UV region . Gd 3 + shows weak vibronic coupling that results in sharp emission and excitation peaks, and weak multiphonon transitions .…”

Synthesis of Dy3+, Eu3+ and Tb3+ Activated Y2O2S Optoelectronic Phosphors for N-UV LED Applications

“…At measurement time slit width of the instrument was fixed at 1.5nm. The co-ordinations in the xy-chromaticity diagram are directly calculated from the fluorescent spectra (CIE 1931) [11]. The sample was found to be non-hygroscopic, stable and whitish in nature.…”