Efficient green indium phosphide quantum dots with tris(dimethylamino)-phosphine phosphorus precursor for electroluminescent devices

摘要

In this study, green indium phosphide (InP) quantum dots (QDs) were synthesized using a tris(dimethylamino)phosphine ((DMA)_3P) phosphorus source and applied to electroluminescent quantum light-emitting diodes (QLEDs). The (DMA)_3P precursor is safer and more cost-effective than the conventional tris(trimethylsilyl)phosphine. The emission peak of the InP QDs was shifted to the green region from the red by replacing the conventional zinc precursor ZnCl_2 with ZnI_2. The surface reaction rate was limited using ZnI_2 in the core formation step, yielding small-sized QDs to achieve green emission. In addition, with the optimal ZnSeS intermediate shell and outer shell, the maximum quantum yield of 67.5% with a narrow full width at half maximum of 46 nm was achieved for the (DMA)_3P-based green-emitting InP@ZnSeS/ZnS QDs. QLEDs were demonstrated with the (DMA)-3P-based green InP QDs, and their efficiency was maximized by optimizing the Mg doping ratios in the electron transport layer (ETL) of ZnMgO. The maximum external quantum efficiency of 1.68% and current efficiency of 4.79 cd/A were achieved with an optimal doping ratio of 12.5% ZnMgO for the (DMA)_3P-based green InP QLEDs. This study demonstrates that safer (DMA)_3P phosphide source-based green InP QDs are effective in achieving low-cost InP QLEDs.