International Journal of Electrical and Computer Engineering (IJECE) Vol. 10, No. 5, October 2020, pp. 5147~5154 ISSN: 2088-8708, DOI: 10.11591/ijece.v10i5.pp5147-5154  5147 Journal homepage: http://ijece.iaescore.com/index.php/IJECE SrBaSiO4:Eu 2+ phosphor: a novel application for improving the luminous flux and color quality of multi-chip white LED lamps Nguyen Thi Phuong Loan 1 , Nguyen Doan Quoc Anh 2 1 Faculty of Fundamental 2, Posts and Telecommunications Institute of Technology, Vietnam 2 Power System Optimization Research Group, Faculty of Electrical and Electronics Engineering, Ton Duc Thang University, Vietnam Article Info ABSTRACT Article history: Received Sep 11, 2019 Revised Apr 22, 2020 Accepted May 5, 2020 This paper described in detail the chromatic homogeneity and luminous flux influences in producing better quality white LED devices with various phosphor layers (MCW-LEDs). The method is to let Eu 2+ -activated strontium–barium silicate (SrBaSiO4:Eu 2+ ) mixed with their phosphor compounding, which results in notable impact on lighting performance. The increase in concentration of yellow-green-emitting SrBaSiO4:Eu 2+ phosphor also promotes the color performance and lumen output of WLED devices at high correlated color temperature around 8500K. This is the first time this approach is applied and it results can be utilized for better understanding of optical properties interaction with phosphor materials. Although SrBaSiO4:Eu 2+ receives many positive responses, we still need to limit it concentration for high SrBaSiO4:Eu 2+ concentration is detrimental to CQS. The appropriate choice of concentration and size of SrBaSiO4:Eu 2+ is the principal factor to decide the performance of MCW-LEDs. Keywords: Color quality scale Luminous flux Mie-scattering theory SrBaSiO4:Eu 2+ WLEDs Copyright © 2020 Institute of Advanced Engineering and Science. All rights reserved. Corresponding Author: Nguyen Doan Quoc Anh, Power System Optimization Research Group, Faculty of Electrical and Electronics Engineering, Ton Duc Thang University, No. 19 Nguyen Huu Tho Street, Tan Phong Ward, District 7, Ho Chi Minh City, Vietnam. Email: nguyendoanquocanh@tdtu.edu.vn 1. INTRODUCTION Recently, perfecting the optical properties of WLED, especially the luminous efficacy and color-related attributes, is a leading research goal of many scientists, which has been mentioned in previous papers [1-5]. After many experiments, Anh and his colleagues discover the mixture of YAG:Ce 3+ phosphor compounding with SiO2 particles could significantly increase the lighting efficiency of white LED lighting devices [6-8]. In addition, the combination of yellow YAG:Ce 3+ phosphor with the silicone substance could support the blue light and yellow light extraction [9-12] and also generate the white light. This process includes two stages: disintegrating in phosphor compounds and moving through phosphor particles, in which the YAG:Ce 3+ phosphor layer will metabolize the blue light and simultaneously make it become weaker [13-16]. However, the converted yellow light tends to be more intense after every scattering, which makes the normal extracted light from the WLED to be more blue, while if it is placed near the LED exterior, the color tend to be more yellow [17-19]. Won was in collaboration with his partner to prove the marked effect of phosphor configuration on the lighting efficiency of LED devices with great color quality scale (CQS), where blue LEDs and multiple phosphor materials such as green (Ba,Sr) 2SiO4:Eu 2+ and red CaAlSiN3:Eu 2+ were applied in various phosphor structures to achieve optimal efficiency [20]. In contrast,