Deep-blue organic light-emitting diodes based on multi-tert-butyl modified naphthylene

Abstract

Six tert-butyls modified naphthyl derivative (2,6-di-tert-butyl-1,5-bis-(3,5-di-tert-butyl-phenyl)-naphthalene (N(dtb)4) was synthesized and tested for host and guest materials in organic light-emitting diodes (OLEDs). Blue OLED using N(dtb)4 as a host and an emitter DSA-PH as a guest reaches an efficiency of 11.52 cd·A−1 (maximum external quantum efficiency 7.8 % and maximum power efficiency 10.33 lm·W−1). In addition, for the OLED with N(dtb)4 being a guest, we find that the concentrations of N(dtb)4 will also affect the performance of the OLED, among which ADN: 5 wt.% N(dtb)4 has higher efficiency, and the maximum current efficiency, external quantum efficiency (EQE) and power efficiency of the device reach 3.75 cd·A−1, 3.93 % and 3.36 lm·W−1, respectively. We also investigated the pure N(dtb)4 -based ultraviolet OLED (UV-OLED), and achieved the maximum EQE of the device is 1.12 %. These results indicate that N(dtb)4, a novel synthesized fluorescent organic material, has great potential applications in OLEDs and accordingly advancing lightings and displays.