A Dual-Color Channel Design Enables Low Flicker, Highly Efficient, and Cost-Effective AC-LEDs

Alternating current-driven light-emitting diodes (ac-LEDs) have made significant advancements in lighting industry, offering key advantages such as high-energy efficiency and ease of integration. However, challenges remain in achieving cost-effective and reliable ac-LEDs with both low flicker and high power-factor (PF). In this study, we proposed an ac-LED architecture that utilizes dual-color channels by incorporating green-yellow phosphor and red K<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><roman>2</roman></sub>SiF<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><roman>6</roman></sub>:Mn<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><roman>4</roman>+</sup> (KSF) phosphor in separate light-emitting diode (LED) strings. The green-yellow phosphor is incorporated into an LED channel with a large duty cycle, where a small capacitor is used to compensate for luminescence. The KSF is incorporated into LED channels with lower duty cycles, leveraging its medium-afterglow characteristic for compensation and reducing capacitor requirement. A 3920 K ac-LED module was developed with achieving less than 10% flicker, a PF of 0.95, and a system luminous efficiency of 182 lm/W. Moreover, this approach reduces total capacitor requirements by 50%–75%, significantly lowing system cost. These results highlight the advantages of medium-afterglow phosphors in ac-LEDs, significantly improving both cost-effectiveness and energy efficiency, which paves the way for their widespread application in the commercial lighting industry.