Enhanced Performance of Red Perovskite Light-Emitting Diodes through the Dimensional Tailoring of Perovskite Multiple Quantum Wells.

Halide perovskite multiple quantum wells (MQWs) have recently shown great potential in the field of light-emitting diodes. We report a facile solution-based approach to fabricate dimensionality-tunable perovskite MQWs by introducing 1-naphthylmethylammonium (NMA) cations into CsPbI3 perovskites. Through the dimensional tailoring of (NMA)2Csn-1PbnI3n+1 perovskite MQWs, the crystallinity and photoluminescence quantum efficiencies (PLQEs) are significantly improved. We have obtained high-performance red perovskite light-emitting diodes (PeLEDs) with a luminance of 732 cd m-2 and a maximum external quantum efficiency of 7.3%, which are among the best-performing red PeLEDs. Significantly, the maximum luminance of our PeLEDs is obtained at a low applied voltage of 3.4 V, with a turn-on voltage close to the perovskite band gap (Vturn-on ≈ 1.9 V). These outstanding performance characteristics demonstrate that dimensional tailoring of perovskite MQWs is a feasible and effective strategy to achieve high-performance PeLEDs, which is attractive for full-color display applications of perovskites.