Highly Efficient Blue Electro-Fluorescence and Hybrid White Electroluminescence Basing on a Novel Hybrid Local and Charge-Transfer (HLCT) Material with Weak Donor-Acceptor Structure and High Carrier Mobilities

High efficiency and luminance are critical for commercialized blue organic light-emitting diodes (OLEDs). Herein, a novel donor-acceptor (D-A) blue-emissive molecule with a weak donor and acceptor is synthesized. The moderate hybrid local and charge transfer (HLCT) state character endows PPIBPO with blue fluorescence and high quantum efficiency. More importantly, the rigid, rod-like molecular structure gives rise to the regularity of the stacking pattern of PPIBPO, which enables its extraordinary carrier mobilities in non-doped OLED, the hole mobility and electron mobility are as high as 5.09 x 10(-5) cm(2) V-1 s(-1) and 3.22 x 10(-4) cm(2) V-1 s(-1), respectively. The non-doped blue OLED of PPIBPO achieves a maximum external quantum efficiency (EQE) of 12.0% and a maximum luminance of 55023 cd m(-2), which is one of the best values among the non-doped blue OLEDs based on HLCT molecules. Furthermore, high-efficiency two-color hybrid warm white OLED with a maximum EQE up to 22.5% and maximum power efficiency of 87.0 lm W-1 is also achieved using PPIBPO as blue-fluorophor.