Highly Bright, Narrow Emissivity of InP Quantum Dots Synthesized by Aminophosphine: Effects of Double Shelling Scheme and Ga Treatment

초록

Indium phosphide (InP) quantum dots (QDs) are in an unrivaled position in photoluminescence (PL) performances particularly for green and red color over other heavy-metal-free QD visible emitters. Herein, based on InP cores synthesized using an easy-to-handle, safe aminophosphine precursor, unprecedented bright, narrow emissivity is demonstrated synergically by optimizing double shelling scheme and Ga treatment. Two comparative double shells of ZnSe0.5S0.5/ZnS versus ZnSe/ZnS are generated on green-emissive InP cores, yielding better PL outcomes with respect to PL quantum yield (QY) and full-width-at-half-maximum (FWHM) from the latter scheme over the former one. With an intent to further enhance emissivity, incorporation of Ga onto InP cores in the course of ZnSe inner shelling is newly devised. Properly Ga-treated InP/ZnSe/ZnS QDs, where Ga is presumed to play a beneficial role in removing surface P dangling bond of InP core, produce a near-unity PLQY (97%) and narrow FWHM of 37 nm. The similar effectiveness is also verified in red InP/ZnSe/ZnS heterostructure, clearly indicating that Ga treatment is a viable, valid strategy toward bright emissivity in the InP QD system.

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