Optical and Electroluminescent Studies of White‐Light‐Emitting Copolymers Based on Poly(9,9‐dioctylfluorene) and Fluorenone Derivatives

Abstract

A novel type of single white‐light‐emitting copolymers, PF‐DTFOx, derived from poly(9,9‐dioctylfluorene) (PF) in which 2,7‐di‐(2‐thienyl)‐9‐fluorenone (DTFO) is introduced as an orange‐emitting unit, is reported, and their application in white‐light polymer light‐emitting devices (PLEDs) is explored. Because of the very simple structure of DTFO, the synthetic routes to PF‐DTFOx are not complicated, and the raw materials are cheap; these are advantageous in reducing the fabrication cost of white‐light PLEDs. In the fluorescence spectra, PF‐DTFOx in solid powder shows dual peaks at around 460 and 560 nm. In white‐light PLEDs, the color of the white‐light emission is tunable; this can be achieved by changing the content of DTFO in PF‐DTFOx. The light‐emission color varies from blue‐white to pure white and orange‐white when the composition of DTFO increases. All the PLEDs based on PF‐DTFOx exhibit maximum luminance above 1800 cd m−2 and a color rendering index above 80. image