Triptycene-fused hole transport material for highly efficient organic light-emitting diodes

Abstract

The improvement of high-performance organic light-emitting diodes (OELDs) is still attracted much attention in research and application fields. In an OLED device, the hole/electron transport layers, emitting layers and electrodes together determine the performance of the device. However, the development of hole transport materials (HTM) is severely fallen behind. Herein, we report a novel triptycene-derived HTM 2,6-di-[4-(N,N-di-p-tolyl-amino)-phenyl]triptycene (TAPT), which can transform the molecule from planar to 3D configuration. Compared with most of commercial HTMs, TAPT exhibits a relatively high T1 of 2.95 eV, which is very helpful for blocking exciton leakage. Moreover, TAPT shows the hole mobility up to 9.73 × 10-5 cm2 V−1 s−1, which are almost two orders of magnitude higher than those commercial HTMs. By using TAPT as hole transport layer (HTL), it is further found that the fabricated OLEDs with various emitters display more preferable device performance than those using TAPC as HTL. This work provides an advanced approach for constructing high-performance hole transport materials and corresponding OLEDs.