White Organic Light-emitting Devices Based On Novel (e)-2-(4-(diphenylamino) Styryl)quinolato Zinc As A Hole-transporting Emitter

摘要

The electroluminescence (EL) characteristics of a novel yellow emitting material, (E)-2-(4-(diphenylamino)styryl)quinolate zinc (TPAHQZn), have been studied according to the device structure of ITO/2T-NATA/TPAHQZn/Alq_3/LiF/Al, which indicates that maximum luminous efficiency reaches up to 0.73 cd A~(-1) (at 10 V) and maximum luminance up to 5838 cd m~(-2) (at 10 V). The yellow light emission peak is located at 590 nm and the Commission Internationale De L'Eclairage (CIE) coordinates slightly vary from (0.5127, 0.4773) at 6 V to (0.4928, 0.4879) at 10 V. In the meantime, TPAHQZn also demonstrates strong hole-transporting ability according to the structure of the device. Then, a series of white devices are fabricated with the structures of ITO/2T-NATA (17 nm)/TPAHQZn (x nm)/NPBX (y nm)/BCP (8 nm)/Alq3 (75-x-y nm)/LiF (0.5 nm)/Al, which has the maximum luminous efficiency of 2.66 cd A~(-1) (at 10 V) and the maximum luminance of 12 930 cd m~(-2) (at 12 V) by adjusting the thicknesses of TPAHQZn and NPBX. Additionally, CIE coordinates slightly vary from (0.3179, 0.3011) to (0.3389, 0.3183) when the voltage shifts from 7 V (348.6 cd m~(-2) to 12 V (12 930 cd m~(-2)).