Flexible Red Quantum Dot Light-Emitting Diodes Enabled by a Highly Conductive and Transparent Poly(benzodifurandione)
Jin Xu1,2, Weiji Feng1, Guohong Cui1
1School of Mechanical Engineering, Dongguan University of Technology, Dongguan523808, China.
Abstract:
As a highly conductive polymer, poly(benzodifurandione) (PBFDO) shows great potential in flexible electrodes. Yet its poor interfacial compatibility with the traditional hole-transport layer PEDOT:PSS limits device performance, posing a key challenge for practical applications. To address this issue, we developed a novel oil-soluble hole-transport system comprising PF8Cz-TPA doped with TrTPFB. TrTPFB p-type doping boosts PF8Cz-TPA's hole transport and work-function matching, enabling its single layer to replace the PEDOT:PSS/PF8Cz-TPA bilayer, improving device performance and simplifying manufacturing. The optimized PBFDO-based red quantum dot light-emitting diode (QLED) delivers exceptional performance: a low turn-on voltage of 1.9 V, a maximum luminance of 39,603 cd m-2, and a peak current efficiency of 15.15 cd A-1. This peak efficiency is about four times that of undoped devices (3.92 cd A-1) and reaches 79% of the performance of ITO-based devices. PBFDO-based devices exhibited superior operational stability, with luminance dropping from 19,000 to 12,000 cd m-2 over 120 h, while ITO-based devices degraded rapidly, falling from 12,000 to 5000 cd m-2 in just 45 h. Flexible QLEDs built on PEN substrates deliver a current efficiency of 10.96 cd A-1, confirming their promising prospects in flexible display technologies.
