Proceedings Article | 3 February 2009
Proc. SPIE. 7231, Light-Emitting Diodes: Materials, Devices, and Applications for Solid State Lighting XIII
KEYWORDS: Energy efficiency, Light emitting diodes, Data modeling, Luminescence, Quantum efficiency, Manufacturing, 3D modeling, Monte Carlo methods, Blue light emitting diodes, Absorption
The use of white LEDs for solid-state lighting to address applications in the automotive, architectural and general
illumination markets is just emerging. LEDs promise greater energy efficiency and lower maintenance costs. However,
there is a significant amount of design and cost optimization to be done while companies continue to improve
semiconductor manufacturing processes and begin to apply more efficient and better color rendering luminescent
materials such as phosphor and quantum dot nanomaterials. In the last decade, accurate and predictive opto-mechanical
software modeling has enabled adherence to performance, consistency, cost, and aesthetic criteria without the cost and
time associated with iterative hardware prototyping. More sophisticated models that include simulation of optical
phenomenon, such as luminescence, promise to yield designs that are more predictive - giving design engineers and
materials scientists more control over the design process to quickly reach optimum performance, manufacturability, and
cost criteria.
A design case study is presented where first, a phosphor formulation and excitation source are optimized for a white
light. The phosphor formulation, the excitation source and other LED components are optically and mechanically
modeled and ray traced. Finally, its performance is analyzed. A blue LED source is characterized by its relative spectral
power distribution and angular intensity distribution. YAG:Ce phosphor is characterized by relative absorption,
excitation and emission spectra, quantum efficiency and bulk absorption coefficient. Bulk scatter properties are
characterized by wavelength dependent scatter coefficients, anisotropy and bulk absorption coefficient.
