The structure and photoluminescence properties of a novel orange emission phosphor Ba_3Sc_(1.9)Al_(0.1)B_4O_(12): Eu~(2+) excited by NUV light

摘要

A novel borate mineral of Ba3Sc1.9Al0.1B4O12 was synthesized successfully by traditional high temperature solid-state reaction. Its structure is determined by High-resolution transmission electron microscopy, Energy Dispersive X-Ray Spectroscopy and X-ray powder diffraction Rietveld refinement. The crystal structure of Ba3Sc1.9Al0.1B4O12 was found to be trigonal crystal system and the space group is attributed to P-3m1 (164). Moreover, a series of Eu2+ doped Ba3Sc1.9Al0.1B4O12 phosphors are investigated. The electron structure, band structure and photoluminescence properties of Ba3Sc1.9Al0.1B4O12: Eu2+ are investigated in detail by density functional theory calculations, diffuse reflection spectra, emission-excitation spectra, decay curves and temperature dependence spectra. It can emit orange light peaking at similar to 592 nm upon 400 nm NUV excitation with quantum efficiency 40.1%. According to structure and photoluminescence (PL) properties analysis, Eu2+ can occupy two kinds of Ba2+ site. The concentration quenching mechanism of Eu2+ could be a d-d interaction luminescence center. It has not good temperature stability properties because of too much temperature-dependent electron-phonon interaction at high temperature. The fabricated white-LEDs using a 370 nm GaN NUV chip combined with orange/blue phosphors under different weight ratio driven by 30 mA current can get series warm-white light, which the correlated color temperature is smaller than 'YAG + Blue chips' It demonstrates that Ba3Sc1.9Al0.1B4O12: Eu2+ is a potential orange phosphor matching NUV LED chips to get warm white light.