Efficient Red-Emissive Circularly Polarized Electroluminescence Enabled by Quasi-2D Perovskite with Chiral Spacer Cation
Changhui Yang, Shang‐Biao Xiao, Hui Xiao, Liang‐Jin Xu, Zhong‐Ning Chen
Abstract
Perovskites are promising environmentally sustainable materials for circularly polarized electroluminescence (CPEL). While another chiral nonemissive layer is required for the developed perovskite-based CPEL, we report herein a highly efficient circularly polarized electroluminescence based on a single layer of quasi-2D perovskite with achiral phenethylammonium iodide (PEAI) and chiral S / R -1-(1-naphthyl)ethylammonium iodide (S/R-NEAI) as dual spacer cations. The quasi-2D perovskite was further passivated by carbazole-functionalized phosphonium. The as-fabricated film exhibits not only a circular dichroism (CD) signal but also prominent circularly polarized luminescence (CPL) activity with a maximum photoluminescence dissymmetry factor ( g lum ) of ∼2.1 × 10 –3 . More importantly, a highly efficient, spin-polarized light-emitting diode (LED) was fabricated based on the in situ passivated quasi-2D perovskite with a peak external quantum efficiency of 3.7% and a maximum electroluminescence dissymmetry factor ( g EL ) of ∼4.0 × 10 –3 .