Efficient single-molecular white-light emission for iridium-based photoluminescent and electroluminescent white OLEDs

The white organic light-emitting diode has become as a new class of emerging solid-state lighting sources due to its advantage of warm, pure white light emission, flexible lighting, and environmentally friendly indoor lighting. Here, we report three rationally designed cyclometalated [3 + 2+1] iridium(Ⅲ) complexes that emit white emission simultaneously from phosphorescent blue and yellow in the solid-state thin film. The blue GaN-based solid-state white light-emitting diodes with iridium(Ⅲ) complexes as a color converter show a color rendering index of 84.4 and International Commission on Illumination (CIE) coordinates of (0.30, 0.33). In addition, the vacuum-deposited organic light-emitting diode device exhibits a low turn-on voltage of 3.0 V and a maximum luminance (L_max) of 335 cd m⁻² with CIE coordinate of (0.31, 0.33), reaching standard naturally warm white light.