Alternating current-driven, white field-induced polymer electroluminescent devices with high power efficiency

A solution-processed, all-phosphor, three-color (i.e., blue, green, and red), alternating current-driven white field-induced polymer electroluminescent device (WFIPEL), with low operational voltage, high luminance, high efficiency, high color-rendering index (CRI), and excellent color-stability, was demonstrated. The devices employed poly(vinylidene fluoride-trifluoroethylene-chlorofluoroethylene) [P(VDF-TrFE-CFE)] dielectric modified by single-walled carbon nanotubes (SWNTs) to further improve the dielectric characteristics, as the insulating layer. This significantly lowers the driving voltage of the device. Moreover, hole-generation layer and electron-transporting layer with high conductivity were used to more efficiently form and confine excitons in the emissive layer. The resulting WFIPEL devices show significant improvements in performance as compared to previous reports. Specifically, the devices exhibit a low turn-on voltage of 10 V, a maximum luminance of 7210 cd m^-2, a maximum current efficiency and power efficiency of 33.8 cd A^-1 and 10.5 lm W^-1, and a CRI of 82. The power efficiency is even 10 times higher than the highest previous report (1 lm W^-1).