High-performance light-emitting diode with poly(ethylene oxide) passivated quasi two dimensional perovskite emitting layer

Two-dimensional perovskites have attracted attention as a kind of potential electroluminescence (EL) materials due to their controllable quantum confine effect, but there are still some inadequacies in their EL efficiency and stability. In this work, the enhanced optical and electrical properties of quasi two dimensional organometal halide perovskite (QTDOHP) passivated by poly(ethylene oxide) (PEO) are reported. The introduction of PEO can not only passivate the surface defects of QTDOHP, but also suppress the formation of low luminous efficient single-layered QTDOHP phase. The photoluminescence quantum yields (PLQY) of the composite film has been approximately increased by 350% compared with pure QTDOHP films. The EL devices based on emitting layer (EML) of PEO-QTDOHP composite film have achieved a brightness of up to 41800 cd/m(2) and a maximal current efficiency of 25.1 cd/A. The EL intensity of the device with PEO dropped to 70% of the initial value after around 7 h under a constant current density of 10 mA/cm(2), which indicates an excellent device operation stability. The composite film of QTDOHP and PEO would serve as distinct and promising materials for light-emitting diode application.