High reliability and luminance of the color wheel by phosphor-in-inorganic silicone

Abstract

High reliability and luminance of the color wheel in a laser light engine (LLE) employing novel phosphor-in-inorganic silicone (PiIS) fabricated at the low temperature of 180°C for laser projector applications is presented and demonstrated for the first time. Yellow (Y3Al5O12:Ce3+) and green (Lu3Al5O12:Ce3+) phosphors were uniformly mixed by inorganic silicone, organic silicone, and glass to fabricate as a phosphor color wheel. The PiIS-based color wheels showed better thermal stability than the phosphor-in-organic silicone (PiOS), about 3-7 times less lumen loss and 7-8 times less chromaticity shift under accelerated aging at 350°C for 1008 hours. The advantage of the PiIS fabricated at a low temperature of 180°C enabled the achievement of excellent thermal performance, which was similar to the phosphor-in-glass (PiG) fabricated at a high temperature of 680°C. The good thermal stability of the PiIS can be attributed to the high glass melting temperature of up to 510°C. Low-temperature fabrication, excellent optical performance, and high reliability of the proposed PiIS-based color wheels benefit as promising candidates to replace the current PiOS or PIG-based color wheels in the LLE modules for the next-generation laser projector applications.