Efficient Non-Doped White Organic Light-Emitting Diodes Based on an Interface Exciplex Structure

Non-doped organic light-emitting diodes (OLEDs) feature simple fabrication processes and favorable repeatability, yet their overall device performance remains unsatisfactory. Here we propose a novel white OLED based on ultrathin emissive layers (EMLs). The novel efficient device structure is constructed based on an interface exciplex structure. Color-stable or color-tunable white OLEDs can be realized by tuning the interlayer thickness. The resulting color-tunable white device obtains a maximum power efficiency of 32.03 lm/W with a correlated color temperature span from 4091 K to 5376 K. Furthermore, the luminescence mechanism is thoroughly investigated. The shift of the spectra in the color-tunable device is mainly attributed to the movement of the main exciton recombination zone.