Efficient perovskite light-emitting diodes with modified hole injection layer

Perovskite materials are considered as candidate for the next generation solid state luminescent materials for their exceptional optoelectronic properties, for instance low defect density, high fluorescence quantum efficiency, and high color fineness. To produce highly efficient perovskite light-emitting diodes (PeLEDs), better-matched energy level alignment between the functional layers is of vital significant. In this work, we use poly (sodium-p-styrene-sulfonate) (PSSNa) modified PEDOT: PSS as the hole injection layer to improve hole injection into perovskite emissive layer and inhibit the interfacial exciton quenching. The external quantum efficiency (EQE) of the CsPbBr3-based PeLEDs is improved from 5.65% to 7.81%.