An Investigation on CCT and Ra Optimization for Trichromatic White LEDs Using a Dual-Weight-Coefficient-Based...

Area of Science:

• Solid-state lighting technology
• Optical engineering
• Materials science for LEDs

Background:

• Spectral optimization is crucial for designing solid-state lighting devices.
• Optimization speed in designing white light-emitting diodes (WLEDs) algorithms remains under-explored.
• Trichromatic WLEDs synthesize white light using blue, yellow, and red monochromatic spectra.

Purpose of the Study:

• To propose an effective spectral optimization method for trichromatic WLEDs.
• To achieve optimal color rendering (Ra) under target correlated color temperatures (CCTs).
• To enhance the speed and accuracy of WLED design algorithms.

Main Methods:

• Utilized blue (GaN LED), yellow (YAG:Ce3+ phosphors), and red (CdSe/ZnSe quantum dots) spectra for white light synthesis.
• Introduced dual weight coefficients to maintain a numerical gap between floating and target CCTs.
• Investigated the interaction mechanisms between CCT, Ra, and dual weight coefficients.

Main Results:

• The dual weight coefficient method effectively ensures simultaneous convergence of Ra and CCT towards target values.
• A linear relationship was identified between weight coefficients and target CCTs, confirmed by a fitting curve.
• Achieved the highest Ra of 96.1 at a target CCT of 4000 K in only 29 iterations.
• Demonstrated accelerated optimization process and maintained accuracy compared to global searching methods.

Conclusions:

• The proposed method significantly accelerates the spectral optimization process for WLEDs.
• Dual weight coefficients are effective in simultaneously optimizing Ra and CCT.
• This research facilitates advancements in illumination technologies, including residential intelligent lighting and smart planting LED systems.