Experimental and first-principles analyses of oxidative defect removal in eco-friendly InP quantum dot synthesis via in situ HF etching

초록

Indium phosphide (InP) colloidal quantum dots (QDs) are promising for next-generation displays. However, synthetic reliance on the addition of aqueous hydrofluoric acid (HF) during the reaction for oxygen-sensitive materials, such as InP QDs, makes synthesis challenging and less safe. Herein, we report a safer, oxygen-free synthetic route for high-quality InP QDs by combining tri(dimethylamino)phosphine [(DMA)3P] (as the phosphorus source) and ZnF2 as an additive in an alkylamine solvent. ZnF2 in situ produces HF, suppressing the formation of polyphosphates (P2O7x-) and mixed oxides (InPOx) and enables the growth of high-quality QDs. Subsequent growth of ZnSe/ZnSeS/ZnS shells results in core/shell QDs with enhanced photoluminescence quantum yield (PLQY) of 93% and 88% for red and green-emitting QDs. We report, red and green light-emitting diodes (LEDs) with external quantum efficiencies (EQEs) of 11.8% and 7.5%, respectively. Our in situ acid management strategy provides a safer way to use HF to etch out oxidative surfaces during the growth of QDs.

키워드