Blue light-emitting diodes based on coronene-doped polymers

The photoluminescent (PL) and electroluminescent (EL) properties of coronene crystalline film, as well as the electrochemical oxidation behavior, were investigated. It was found that coronene can be used as a good hole-transporting and light-emitting material. Coronene was doped into the hole-transporting polymer poly (N-vinylcarbazole) (PVK), the obtained blends were used as emitting layers for the fabrication of blue light-emitting diodes (LEDs). The double-layer device using 2,5-bis (5′-tert-butyl-2-benzoxazolyl) thiophene (BBOT) as an electro-transporting layer exhibited better performance than single-layer device made of blend only. The working parameters of double-layer device include the turn-on voltage of 3.7 V, maximum brightness of 1700 cd/m2, peak emission wavelength at 453 nm, and external efficiency of 0.8%.