AC-Driven LED Phosphors
Hang Lin, Yuansheng Wang · 2021
The alternative current (AC)-LED, directly using AC instead of direct current (DC) as the driving source, shows great superiorities of low-cost, high-energy utilization efficiency, and long service life, over the DC-LED counterparts. However, the light flicker in AC cycles needs to be restrained. This chapter covers the up-to-date AC-LED technology (including AC-LED configuration, circuit design, and light engine), the light flicker phenomenon and its hazardous effect to human health, as well as, the theoretical background, design principle, material system, and luminescent performance of AC-LED phosphors. Some typical cases of researches, utilizing millisecond-ranged short decays of AC-LED phosphors to suppress the light flicker, are highlighted, attempting to guide the search for this special kind of storage material in the future. Finally, some challenging issues are discussed and potential directions are suggested for further developing the persistent phosphor-converted AC-LED technology.