Naphthalene-Arylamine starburst architectures: Novel hole transport materials for enhanced OLED performance

The excellent hole transfer material (HTM) is beneficial to improve the stability of the device, reduce turn-on voltage(V_on) and make full use of the potential performance of the developed emissive materials. In this work, we designed and synthesized four HTMs with triarylamine and naphthalene compounds - SHT1- SHT4. The characteristics of these four compounds were investigated by TGA, DSC. UV–vis absorption and photoluminescence spectra. These four HTMs all exhibit excellent hole transmission capability for their high triplet energy levels (E_T), outstanding thermal property, morphological stabilities and appropriate highest occupied molecular orbital (HOMO) energy levels with emissive layer (EML). Four top-emission blue OLEDs with SHT1 - SHT4 as hole transport layer (HTL) were fabricated and show good electroluminescence (EL) property. The results show that the device incorporating SHT3 exhibit the best device performances with a low V_on of 2.79 V, external quantum efficiency (EQE_max) of 19.7 %, highest current efficiency (CE_max) and highest Power efficiency (PE_max) of 8.86 cd A⁻¹ and 9.05 lm/W, respectively.