Pure hydrocarbon host materials based on spirofluorene with excellent performances for green phosphorescent light-emitting devices

Abstract

Four pure hydrocarbon molecules based on spirofluorene were synthesized and their optoelectronic properties were investigated. These four compounds (1–4) exhibited excellent optoelectronic properties with good thermal stabilities, favorable optical energy bandgaps and triplet energies, compatible HOMO–LUMO energy levels and so on. Green phosphorescent organic light emitting devices (PHOLEDs) in which these four compounds served as host materials have been fabricated, and compound 1 demonstrated the optimal electroluminescence (EL) performance with a maximum current efficiency, maximum power efficiency and external quantum efficiency (EQE) of 31.5 cd A⁻¹, 19.8 lm W⁻¹ and 9.0%, respectively, which make it a promising candidate as a host material for PHOLEDs.