Enhanced Electroluminescence Properties of Tin-based Perovskites by Vitamin C Additives
Lead halide perovskite light-emitting diodes with tunable light emission,high luminance,high external quantum efficiency,wide color gamut,low cost and solution processable are promising candidates for solid-state lighting,ultrahigh-definition displays and optical communications.However,lead halide perovskites are toxic and harmful to both the human body and environment,which are therefore not in line with the concept of sustainable de-velopment.Two-dimensional phenylethylammonium tin-iodide(PEA2SnI4)perovskites with pure red emission are ex-pected to become next-generation red light-emitting materials for displays due to their advantages of ultrahigh color purity,ultrawide color gamut(close to the Rec.2020 standard),and environmental friendliness.However,the fast-er growth rate of tin-based perovskite films compared to lead-based perovskites results in poorer quality films,and Sn2+ ions are easily oxidized to Sn4+,resulting in nonradiative composites.The electroluminescence(EL)performance of pure red PeLEDs prepared based on PEA2SnI4 is poor and lags far behind that of Pb-based PeLED devices.Here,we demonstrate that vitamin C is an effective multifunctional additive,which reduces the crystallization of the perovskite and improves the quality of the film by interacting with PEA2SnI4.Vitamin C can also significantly reduce the trap density and the nonradiative recombination rate by preventing the oxidation of Sn2+ to Sn4+.After addition of the vitamin C,the PeLEDs exhibit enhanced EL properties,with the maximum brightness and the maximum external quantum efficiency increasing from 67.6 cd/m2 and 0.2%to 513.6 cd/m2 and 0.68%,respectively.This work indi-cates the red-emitting PeLEDs based on PEA2SnI4 have great potential applications in the field of displays,and also provides ideas for the preparation of highly efficient tin-based perovskite materials.
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NSTL
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维普
