Taming a white led
Maryna Meretska is PhD student in the research Group of Complex Photonic Systems . Her supervisor is Professor Willem Vos from the Faculty of Science and Technology.
Since Edison's invention, the technology of white light sources has evolved tremendously. The Nobel prize-winning technology of the blue LED allowed to create energy-efficient white LEDs. These light sources are the most energy efficient sources that can produce white light, and therefore allows the worldwide proliferation of lighting.
In spite of the extensive use of solid-state lighting in everyday life and the apparent simplicity of the physical processes occurring in a white LED, there was to date no analytical theory that could predict the color of a white LED. The primary challenge arises from the lack of physical understanding of systems where the emission coexists with multiple scattering and absorption of light. Due to these properties, widely used analytical tools fail to describe a white LED.
In this thesis prepared in close collaboration with Philips Lighting, the experimental and theoretical tools were defined that analytically connect design parameters of a white LED to its color point. The proposed method allows to explore the large parameter space that pertains to any material used in white LED production. This model provides for the fast and efficient design, resulting in a reduction of both design and production costs. Widespread adoption of our design approach will lead to an increased proliferation of efficient white light sources, even in remote locations with little technological infrastructure.
