Luminescence properties of pigment-coated Y2O3: Eu red phosphor with alpha-Fe2O3 by different coating methods and various exciting energy source

Abstract

Eu3+-doped Y2O3 red phosphor was prepared in order to study the relationship between variation of Eu3+ content and an excitation source such as low and high voltage energy and a vacuum ultraviolet (147 nm), The luminescence properties of pigment-coated (Y2O3Eu)-Eu-: by various coating methods and different energy sources were also investigated. Excitation under a vacuum ultraviolet (VUV) for the red phosphor with different amounts of Eu3+ activator exhibited similar luminescence property with the case of being excited by electrons accelerated under low voltage conditions, The surface of Y2O3:Eu red phosphor was treated with alpha-Fe2O3 pigment by two different methods to improve color purity. One was the adsorption utilizing alpha-Fe2O3 submicron-particles on the phosphor and the other was a precipitation method utilizing Fe(NO3)(3)-urea or hexamethylenetetramine (HMTA), The red phosphor treated with an increasing amount of alpha-Fe2O3 showed decreasing luminescent intensity, but the color purity improved. The luminescent properties of phosphor treated with alpha-Fe2O3 pigment by the adsorption method exhibited much less dependency on the applied energy source. Surface treatment by the precipitation method. however, resulted in much a faster decrease of luminescent intensity with a lowering of the applied voltage and VUV region because of a more homogeneous coating of alpha-Fe2O3 pigment on the phosphor