Cbncentration and temperature dependent luminescence properties of Gd2MoO6:Eu3+ and white light generation from g-C3N4/Gd2MoO6:Eu3+ composite phosphor

摘要

The design and discovery of novel near-ultraviolet excitable phosphors has become a hot topic in academic research and practical applications, such as white light-emitting diodes for solid state lighting. The present work firstly reports the concentration/temperature dependent luminescence properties of the red emitting phosphor Gd2MoO6:Eu3+, synthesized by a typical solid state method. The as-prepared phosphor possesses a single monoclinic phase, as determined from XRD results. Upon excitation with near-ultraviolet light, the (GdMoO6)-Mo-2:Eu3+ phosphor exhibits a characteristic red emission corresponding to the 4f-4f transitions of the Eu3+ ions, in which the main electric dipole transition is D-5(0) -> F-7(2). In addition, the concentration quenching mechanism and the activation energy for thermal quenching of the Eu3+ ions in Gd2MoO6 host was also investigated in detail. Furthermore, a series of novel near-ultraviolet excitable emitting-color tunable composite phosphors consisted of graphitic-phase nitrogen carbon (g-C3N4) and Gd2MoO6:Eu3+ is reported herein. It is interesting that white light emission is veritably generated by compositing two luminescence materials at an appropriate weight ratio of g-C3N4 to Gd2MoO6: Eu3+. The combination of an n-UV LED chip with the composite g-C3N4/Gd2MoO6:Eu3+ phosphor produces white light with a CRI value of similar to 80.1 and a CCT value of 4244 K. The obtained results indicate that the Gd2MoO6:Eu3+ and g-C3N4/Gd2MoO6:Eu3+ phosphors could be potential red and white emitting phosphors for application in white light-emitting diodes. (C) 2017 Elsevier Ltd. All rights reserved.