摘要
Effects of tilt angles of reflective cup structure and phosphor surface geometries on light extraction efficiency and angular color uniformity （ACU） of phosphor converted light emitting diodes （pcLED） are investigated by Monte Carlo ray-tracing simulations. It is found that tilt angles of reflective cup and phosphor surface geometries affect the light extraction efficiency and the ACU distinctly. When the tilt angle varied from 60° to 15°, the light extraction efficiency of LED can achieve the improvements of 13.87%, 18.25% and 14.79% respectively, when the phosphor surface geometry is concave, flat and convex, respectively. It is also found the variety law of phosphor concentrations with the change of tilt angles and phosphor surface geometries to maintain a fixed correlated color temperature （CCT）.
Effects of tilt angles of reflective cup structure and phosphor surface geometries on light extraction efficiency and angular color uniformity （ACU） of phosphor converted light emitting diodes （pcLED） are investigated by Monte Carlo ray-tracing simulations. It is found that tilt angles of reflective cup and phosphor surface geometries affect the light extraction efficiency and the ACU distinctly. When the tilt angle varied from 60° to 15°, the light extraction efficiency of LED can achieve the improvements of 13.87%, 18.25% and 14.79% respectively, when the phosphor surface geometry is concave, flat and convex, respectively. It is also found the variety law of phosphor concentrations with the change of tilt angles and phosphor surface geometries to maintain a fixed correlated color temperature （CCT）.
基金
The authors would like to acknowledge the financial support in part from the Major State Basic Research Development Program of the Ministry of Science and Technology of China （No. 2011CB013105）, and in part by the National Natural Science Foundation of China （Grant No. 2011AA03A109）.
