Tin-Based Multiple Quantum Well Perovskites for Light-Emitting Diodes with Improved Stability

Tin-based halide perovskites have attracted considerable attention for nontoxic perovskite light-emitting diodes (PeLEDs), but the easy oxidation of Sn2+ and nonuniform film morphology cause poor device stability and reproducibility. Herein, we report a facile approach to achieve efficient and stable lead-free PeLEDs by using tin-based perovskite multiple quantum wells (MQWs) for the first time. On the basis of various spectroscopic investigations, we find that the MQW structure not only facilitates the formation of uniform and highly emissive perovskite films but also suppresses the oxidation of Sn2+ cations. The tin-based MQW PeLED exhibits a peak external quantum efficiency of 3% and a high radiance of 40 W sr-1 m-2 with good reproducibility. Significantly, these devices show excellent operational stability with over a 2 h lifetime under a constant current density of 10 mA cm-2, which is comparable to that of lead-based PeLEDs. These results suggest that perovskite MQWs can provide a promising platform for achieving high-performance lead-free PeLEDs.