Bi-layers red-emitting Sr2Si5N8:Eu2+ phosphor and yellow-emitting YAG:Ce phosphor: A new approach for improving the color rendering index of the remote phosphor packaging WLEDs

Abstract

Due to optimal advances such as chromatic performance, durability, low power consumption, high efficiency, long-lifetime, and excellent environmental friendliness, white LEDs (WLEDs) are widely used in vehicle front lighting, backlighting, decorative lighting, street lighting, and even general lighting. In this paper, the remote packaging WLEDs (RP-WLEDs) with bi-layer red-emitting Sr2Si5N8:Eu2+ and yellow-emitting YAG: Ce phosphor was proposed and investigated. The simulation results based on the MATLAB software and the commercial software Light Tools indicated that the color rendering index (CRI) of bi-layer phosphor RP-WLEDs had a significant increase. The CRI had a considerable increase from 72 to 94. In conclusion, the results showed that bi-layer red-emitting Sr2Si5N8:Eu2+ and yellow-emitting YAG: Ce phosphor could be a prospective approach for manufacturing RP-WLEDs with enhanced optical properties.