Indonesian Journal of Electrical Engineering and Computer Science
Vol 27, No 3: September 2022

High stability in color chromaticity of warm white emitting diode with dual-hue SrSi2O2N2:Eu2+,Yb2+ phosphor

My Hanh Nguyen Thi (Industrial University of Ho Chi Minh City)
Phan Xuan Le (Van Lang University)
Nguyen Le Thai (Nguyen Tat Thanh University)



Article Info

Publish Date
01 Sep 2022

Abstract

In this study, we analyzed and developed a phosphor with a nitridiosilicate based and emitting color changing from green to orange to apply to our white-light-emitting diodes (WLEDs). Eu2+ and Yb2+ trap sites of two-doped SrSi2O2N2:Eu2+,Yb2+ (SrYb) nitridosilicate emit a wide emission in the region between green and orange. Through calculating the decompose time of the green-emission power donor, we could determine the converted energy between the active ions. Furthermore, we also analyzed the impact of co-doping with varied active ion ratios on the photoluminescence (PL) characteristics. As the concentration of Yb2+ increases, the red emission dominates the green. This was because the obtained phoshor's emission depended on the activator ion components. To generate white light, a combination of the acquired phosphor and the InGaN blue LED chip with a 450 nm wavelength was used. With only two steps, we could detect the hue balance management. Firstly, by modifying the Eu2+ and Yb2+ concentration, we can conduct a green-to-orange proportion optimization. Following that, the commission onillumination (CIE) coordinates were transformed to [0.4071; 0.3789] from the original position, which was [0.2805; 0.2014] by enhancing the phosphor powder amount. An environment which has a CRI of around 89 is the optimum condition for conducting white light.

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