Two-Dimensional Mixed Lead-Tin Halide Perovskites for Visble Light-Emitting Diodes

Lead halide perovskites as a new generation of outstanding semiconductor materials have attracted considerable attention. The excellent optical properties and emission qualities makes this kind of materials suitable for light emitting diodes (LED). However, the toxicity of lead limits its large-scale industrial production. Here, we report the gradual reduction of lead content in two-dimensional perovskites by substituting lead with non-toxic tin for preparation of two-dimensional perovskites light-emitting diodes (PeLEDs) with different tin-lead ratios. Among these devices, the lead-free PeLEDs exhibits electroluminescence at 615 nm with peak luminance of 117 cd/m
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and maximum external quantum efficiency (EQE) of 0.18%.