Design And Preparation Of Phosphor Converted Materials For Ultra-High Brightness Or High Uniformity Laser Light Source Application

The phosphor-converted laser lighting technology shows great potential application in super brightness lighting owing to its high power,compactness and energy saving.At the same time,the laser diode with high power density raises higher standard for the design and preparation of laser-driven phosphor materials.In this thesis,component design and structural modification have been adopted to tailor the luminescent properties of materials.Combining the experimental evidences and calculation results,the relationship between the composition and performance(thermal saturation performance,luminous uniformity)of phosphor material is quantitatively analyzed.Laser phosphors with high brightness and optical performance are obtained.(?)Thermal saturation of typical Ce3+-doped garnet phosphor ceramics was systematically investigated by considering the balance among heat generation,dissipation and resistance of color converters.The increase in Ce concentration(0.0167?0.433%)decreases the thermal saturation threshold(35.8613.46 Wmm-2),which is dominated by heat generation.Since the host composition can affect thermal resistance and heat generation,the tunable saturation threshold(2?49 Wmm-2)was observed by a chemical substitution strategy.In addition,the sample thickness exerts a complex influence on the saturation performance,but it is subject to the competitive relationship between the heat generation and heat dissipation corroborated by a broader temperature distribution curve.(?)Based on the investigations of thermally-induced saturation,a high-flux white light of 2347.9 lm is obtained with robust YAG:Ce ceramics irradiated with a high power density of 31.94 W mm-2.Moreover,a promising green color converter able to withstand a blue laser power decsity of 49 Wmm-2 was discovered for high power laser displays with an output luminous flux of 3967.3 lm.(?)Laser lighting puts demanding requirements on luminous uniformity and efficiency of phosphor materials.We thus design a series of YAG:Ce-Al2O3 phosphor-in-glass(PiG)films with various alumina scattering groups.Comprehensive analyses have done on the scattering,heat dissipation and luminous efficiency stabilize effects of alumina.The study of the inevitable trade-off between light uniformity and luminous efficiency.A YAG:Ce-Al2O3 PiG film with uniform illuminance and color temperature was designed by composition optimization,whose maximum output luminous efficiency reached 155.07 lmW-1.This work provides a principle to design and/or select phosphor materials for high brightness and optical uniformity laser light application,thus accelerating the rapid development of laser-driven lighting and displays.