Precise Optical Modeling of Phosphor-Converted LEDs With Arbitrary Concentration and Thickness Using Bidirectional Scattering Distribution Function

Abstract

Phosphor-converted light-emitting diode (pcLED) is one of the most promising methods to generate white light. The interaction of the excitation light with the phosphor in pcLED is a complicated phenomenon, combining light absorption, light conversion, and scattering. An effective and efficient way to predict the optical behavior of pcLED is using the bidirectional scattering distribution function (BSDF). In this paper, the BSDF for pcLEDs with arbitrary phosphor concentration and thickness was established. The measured integrating energy and angular distributions of BSDF were successfully fitted by the interpolation method and the ABg model, respectively, realizing the calculation of BSDF values for arbitrary phosphor configurations. The proposed model was applied to a remote pcLED using an arbitrary phosphor configuration in Monte Carlo simulation. The output radiant power and the angular distributions of the blue and yellow light show good agreements between experiments and simulations; the errors of radiant power were all less than 4%, validating the effectiveness of the model. Consequently, this study provides a simple and useful tool to precisely predict the optical performance of pcLEDs with arbitrary concentration and thickness, it is essential for white LED design and fabrication.

Construction and Optimization of Through-Hole LED Models for Use in Designing Traffic Signboards

“…(3) Figure 11 shows the NCC values calculated at all the distances that we have measured our representative angular intensity distribution, which are 10,15,20,25,35,50, and 100 mm. The graph shows that there is a trend where, as the co-vortex lowers, the NCC values steadily increases, but we still see no signs of a peak or saturation.…”

“…Existing modeling techniques would start from modeling the bare die [12,13], then proceed to model the phosphor scattering and conversion efficiency [14,15] to obtain the complete model. However, for off-the-shelf through-hole LEDs, the die and phosphor data are commonly not published, making such modeling not feasible.…”

“…As seen in Figure 1, the through-hole LEDs are approximately axial symmetric. Although the LED die is not axial symmetric, we assume the scattering properties of the phosphor and dimensions of the cup have made the light source effectively an axial symmetric Lambertian emitter [15]. In addition, for our final application, dot-matrix LED signs, the nonsymmetrical effects are not a main concern.…”

Effect of Amorphous Photonic Structure Surface Mounted on Luminous Performances of White LED

“…Many people find that flat devices show similar LEEs compared to the structured devices [2,10,23,24]. However, the TIR and Fresnel losses still remain on the light extraction surface [11,16,[25][26][27], which should be alleviated to enhance the LEE of white LEDs.…”

Angular Color Uniformity Enhancement for Color-Mixed LEDs by Introducing a Diffusing Coating Layer

“…One of the most popular methods is using a blue LED excitation long wavelength phosphor (such as red, yellow and green phosphor, etc.) to obtain white light (pc-LEDs) [4]. The other is using color-mixed LEDs (cm-LEDs), which is based on multicolor LED chips (such as red, yellow, green and blue LED, etc.)…”