Abstract
Lighting is a crucial technology that is used in our daily lives. The introduction of the white light emitting diode (LED), which consists of a blue LED combined with a phosphor layer, greatly reduces the energy consumption for lighting. Despite the fast-growing market, white LEDs are still being designed with slow, numerical, trial-and-error methods. Here we introduce a radically new design principle that is based on an analytical model instead of a numerical approach. Our model predicts the white LED's color point for any combination of design parameters. In addition, our model provides the reflection and transmission coefficients of the scattered and re-emitted light intensities, as well as the energy density distribution inside the LED. To validate our model, we have performed extensive experiments on an emblematic white LED and found excellent agreement. Our model provides for a fast and efficient design, resulting in reductions of both design and production costs.
| Original language | English |
|---|---|
| Pages (from-to) | 3070-3075 |
| Number of pages | 6 |
| Journal | ACS Photonics |
| Volume | 6 |
| Issue number | 12 |
| Early online date | 26 Jul 2019 |
| DOIs | |
| Publication status | Published - 18 Dec 2019 |
Funding
It is a great pleasure to thank Jan Jansen from Philips Lighting for sample fabrication, Cornelis Harteveld for technical support, Diana Grishina, Oluwafemi Ojambati, Ravitej Uppu, and Shakeeb Bin Hasan for useful discussions, and Nono Groenen for helping with Figure 1 and the TOC figure. This work was supported by the Dutch Technology Foundation STW (contract no. 11985) and by the NWO-FOM program “Stirring of Light!” and by the NWO-TTW program “Free form scattering optics” and by NWO Rubicon Grant 019.173EN.010, by the Dutch Funding Agency NWO and by MESA+ Applied Nanophotonics (ANP).
Keywords
- absorption
- color point
- phosphor
- radiative transport
- scattering
- white LED
