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The light output and reliability testing of the GaN-based blue light-emitting diode (LED) packaging have been carried out with TiO2 nanoparticles (NPs) doped into silicone encapsulation. The LED samples including pure silicone and silicone with various doping concentrations of TiO2 NPs were fabricated and analyzed. The average refractive index of silicone doped with TiO2 NPs with an average diameter of 21 nm was increased while the light extraction efficiency of GaN-based blue LEDs was also enhanced. Moreover, doping the silicone encapsulation with 0.0002 wt % TiO2 NPs could increase the light extraction efficiency by 4.1%. By analyzing the optical-thermal properties, reliability testing, and refractive index of silicone encapsulation, we also demonstrated that doping silicone encapsulation with TiO2 NPs not only enhanced the light extraction efficiency but also improved the reliability of LEDs compared with that of LEDs without TiO2 NP doping. It was considered that the increase in the average refractive index and light scattering reduced the internal reflection loss at the silicone encapsulation between air interfaces, thereby significantly reducing the heat accumulation in LED packaging.

TiO2 nanoparticles (NPs) are doped in silicone for encapsulation of GaN-based blue light-emitting diodes (LEDs). The average refractive index of silicone is increased by doping TiO2 NPs with an average diameter of 21 nm, and the light extraction efficiency of GaN-based blue LEDs is also increased. Four different TiO2 NPs doping profiles are evaluated including without TiO2 NPs doping, uniform doping, doping around the LED chip only, and doping in the region far from the LED chip. LED, with TiO2 NPs (weight percentage of 0.01%) doping around the LED chip only, has the highest luminous flux of 0.98 lm at 20 mA. The conventional blue LED without TiO2 doping has the luminous flux of 0.94 lm at 20 mA. According to our calculations based on the experimental results, the enhancement of the luminous flux is 3 and 5% higher than that without TiO2 doping packages at 20 and 80 mA, respectively. TiO2 doped in silicone can not only increase the luminous flux but also inhibit the lumen degradation under the stress test for 1500 h.