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

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. Copyright © 2015 John Wiley & Sons, Ltd.