A novel thermally stable Ba3Bi2(BO3)4:Eu3+ red phosphor for solid state lighting application

Abstract

This paper reports the structural and optical properties of novel Ba3Bi2(BO3)4:Eu3+ red-emitting phosphor. Concentration series of Ba3Bi2(BO3)4:Eu3+ powders were prepared using crystallization from a melt. Powder X-ray diffraction data confirmed formation of single phase samples. Distribution of Eu3+ ions over three cation sites were refined for Ba3(Bi1-xEuх)2(BO3)4 solid solutions (x = 0.05, 0.35 and 0.8) from single-crystal XRD data. Emission and excitation spectra of Eu3+-doped Ba3Bi2(BO3)4 phosphors show characteristic lines attributed to the intraconfigurational 4f-4f transitions. The optimal Eu3+ doping concentration in Ba3Bi2(BO3)4 host was found to be 50 at.%, whereas concentration quenching phenomenon occurred through dipole-dipole interaction. 5D0 lifetime slightly changed with increase of doping concentration, showing average value of 1.64 ms. The CIE chromaticity coordinates of Ba3Bi2(BO3)4:Eu3+ 50 at.% phosphor was determined to be (0.65, 0.35) which is close to the NTSC standard values (0.67, 0.33) for potential red phosphors. The obtained results show that the Ba3Bi2(BO3)4:Eu3+ phosphors are promising candidates for solid state lighting application.