High-Efficiency Light-Emitting Diodes based on Formamidinium lead bromide nanocrystals and solution processed transport layers

TL;DR

This paper reports the fabrication of high-efficiency perovskite nanocrystal LEDs using solution-processed transport layers and room-temperature synthesized nanocrystals, achieving record brightness and efficiency without vacuum deposition.

Contribution

It introduces a novel, scalable fabrication method for high-performance perovskite LEDs using solution processing and air-synthesized nanocrystals.

Findings

Maximum external quantum efficiency of 6.04%

Luminance of 12998 Cd/m2

High photoluminescence quantum yield of 90% retained in films

Abstract

Perovskite nanocrystal light-emitting diodes (LEDs) employing architecture comprising a ZnO nanoparticles electron-transport layer and a conjugated polymer hole-transport layer have been fabricated. The obtained LEDs demonstrate a maximum external-quantum-efficiency of 6.04%, luminance of 12998 Cd/m2 and stable electroluminescence at 519 nm. Importantly, such high efficiency and brightness have been achieved by employing solution processed transport layers, formamidinium lead bromide nanocrystals (CH(NH2)2PbBr3 NCs) synthesized at room-temperature and in air without the use of a Schlenk line, and a procedure based on atomic layer deposition to insolubilize the NC film. The obtained NCs show a photoluminescence quantum yield of 90% that is retained upon film fabrica-tion. The results show that perovskite NC LEDs can achieve high-performance without the use of transport layers deposited through evapo-ration in ultra-high-vacuum.