High-Performance Blue Perovskite Light-Emitting Diodes Enabled by Synergistic Effect of Additives

Abstract

While quasi-two-dimensional (quasi-2D) perovskites have good properties of cascade energy transfer, high exciton binding energy, and high quantum efficiency, which will benefit high-efficiency blue PeLEDs, inefficient domain distribution management and unbalanced carrier transport impede device performance improvement. Herein, (2-(9H-carbazol-9-yl)ethyl)phosphonic acid (2PACz) and methyl 2-aminopyridine-4-carboxylate (MAC) were simultaneously introduced to a blue quasi-2D perovskite film. Relying on the synergistic effect of 2PACz and MAC, it not only modulates the phase distribution inhibiting the n = 2 phase but also greatly improves the electrical property of the quasi-2D perovskite film. As a result, the as-modified blue quasi-2D PeLED demonstrated an external quantum efficiency (EQE) of 17.08% and a luminance of 10142 cd m −2 . This study exemplifies the synergistic effect among dual additives and offers a new effective additive strategy modulating phase distribution and building balanced carrier transport, which paves the way for the fabrication of highly efficient blue PeLEDs.

Host–Guest Doping Strategy Enables Efficient Perovskite Light-Emitting Diodes with Suppressed Roll-Off

“…In order to minimize the formation of grain boundaries and surface defects in perovskite films, defect passivation is a commonly employed strategy. − Lewis bases are commonly used as passivation additives in PeLEDs. Lewis base molecules containing P, N, S, and O atoms can provide electrons to uncoordinated Pb 2+ in perovskite. − The electrostatic potential (ESP) of TPBi was computed using density functional theory (DFT) to evaluate its interaction with the perovskite.…”