Facile synthesis of Ca0.68Si9Al3(ON)16:Eu2+ microbelts mat with the enhanced fluorescence and mechanical performance

Abstract

Yellow-emitting phosphor mat consisting of Ca0.68Si9Al3(ON)16:Eu2+ microbelts was prepared by electrospinning and subsequent nitridation. The as-prepared fiber precursor is smooth and uniform with diameter of 800 to 900nm. After removing organic templates and nitridation, the morphology of the fiber is well retained and thus a smooth microbelts phosphor mat was obtained. X-ray diffraction and the photoluminescence (PL) spectra reveals that a relatively pure Ca0.68Si9Al3(ON)16 phase and the highest spectral intensity could be obtained at a relatively low temperature of 1500°C and Eu2+ doping molar concentration of 0.1. The excitation spectra exhibits a broad band, ranging from 300 to 550nm, which could be excited by blue LED chip at room temperature. The emission spectra of all exhibits a single broad band in the 400 to 700nm region, with the maximum intensity always being at 580nm. The Ca0.68Si9Al3(ON)16:Eu2+ microbelts phosphor mat has the bending strength about 4.5MPa with a photoluminescence quantum yield as high as 65%. By employing it as yellow phosphor, a high-performance warm white LED could be fabricated with low correlated color temperature (2985K), high-color-rendering index (Ra=86) and luminous efficacy of 129.5lmW−1. Different color temperatures also could be tuned by employing microbelts phosphor mats with different thicknesses.