Strong circularly polarized electroluminescence based on chiral salen-Zn(ii) complex monomer chromophores

Abstract

In this work, two chiral salen-Zn(II) complex enantiomers (R-/S-ZnL) were shown to exhibit weak blue-green colored circularly polarized luminescence (CPL) signals with dissymmetry factors (g_em) of the order of about 10⁻³ both in THF solution and KBr pellet-dispersed state. The R-/S-ZnL enantiomers were used to fabricate circularly polarized organic light-emitting diodes, obtaining values of 1000 cd m⁻², 0.181 cd A⁻¹ and 0.074 lm W⁻¹ for the maximum brightness, current efficiency and power efficiency, respectively, and the dissymmetry factor of the electroluminescent devices (g_EL) could reach ±0.044 at around 490 nm. This study first reports circularly polarized electroluminescence (CP-EL) based on a salen-Zn(II) complex chromophore, which can provide a new strategy for developing promising CP-EL materials.