Fig. 1: Device structure and driving methods of the multifunctional LED.

a Schematic device structure of the multifunctional tandem LED with an extractable IZO intermediate electrode. The Y-QLED and B-OLED can be connected either in parallel or in series. Under parallel connection and AC driving, a color-tunable device is achieved. Under series connection and DC driving, a white-emitting device is obtained. b Energy level alignment of the multifunctional tandem LED.