Optimization of a triazine-based acceptor (CN-T2T) as the electron transport layer for highly efficient near-infrared perovskite light-emitting diodes

Abstract

Near infra-red perovskite light-emitting diodes (NIR PeLEDs) with high efficiency show potential in display panels, security systems, medical therapeutics, spectroscopy and various other applications. An alternative material, namely 3′,3′′′,3′′′′′-(1,3,5-triazine-2,4,6-triyl) tris(([1,1′-biphenyl]-3-carbonitrile)) (CN-T2T), is investigated herein as an electron transport layer (ETL) for efficient solution-processed NIR PeLEDs. In this work, we focused on controlling the thickness of CN-T2T to optimize the device performance. Several electrical properties were investigated to evaluate the influence of CN-T2T. As a consequence, the best performance of NIR PeLED was achieved with an optimized thickness of 50 nm CN-T2T due to adequate charge balance and favorable location of the recombination zone in the active layer. The NIR PeLED device with 50 nm CN-T2T thickness exhibited a maximum EQE of 18.01% and radiance of 366.76 W sr⁻¹ m⁻². Our findings suggest CN-T2T as an alternative ETL that has the potential to improve the performance of NIR PeLED significantly towards the development of high-power NIR LEDs for practical applications.