Multifunctional NdBr3 Modifier Enables Remarkable Enhancement in the Performance of Perovskite Light-Emitting Diodes

Quasi-two-dimensional (quasi-2D) perov- skites possess the preponderances of large exciton binding energy and quantum confinement effects compared with three-dimensional (3D) perovskites. The unique properties of quasi-2D perovskite have attracted extensive attention in the field of optoelectronic devices, especially in the light emitting diode (LED) direction. However, the adverse effects between the perovskite emission layer and the popularly used hole transport layer (HTL) Poly(3,4-ethylenedioxythiophene):poly (styrene sulfonate) (PEDOT:PSS) have degrade the device performance, such as large energy level barrier and exciton quenching. Here we demonstrated high performance of LED with enhanced brightness and efficiency by modifying the PEDOT:PSS with NdBr3, which not only decreases exciton quenching, but also decreases HOMO level of the PEDOT:PSS, thereby improving the charge balance. The final performance of the perovskite light-emitting diode (PeLED) device was obtained with a maximum luminance of 18684 cd m−2, a maximum current efficiency (CE) of 48.4 cd A−1 and an external quantum efficiency (EQE) of up to 15.5% when using NdBr3 modified PEDOT:PSS.

I. Introduction

Metal halide perovskite (MHP) materials have made significant progress in photoelectric direction because of its wonderful photoelectric properties, such as good color purity, high photoluminescence quantum yield (PLQY), high carrier mobility, and tunable spectra [1], [2], [3]. Quasi-2D perovskites are considered as the most promising materials owing to their strong dielectric and quantum confinement effects, which give them high exciton binding energy [3], [4], [5]. These advantages lead to more efficient radiative recombination [6], [7], [8], which is thought to contribute to the development of perovskite light-emitting diodes (PeLEDs).