Controlling Thickness of ZnSe Intermediate Shell Narrows FWHM of Green‐Emitting Spectra of InP/ZnSe/ZnS Multi‐Shell Quantum Dots

The ZnSe thickness of green-emitting InP/ZnSe/ZnS QDs effects on the full width at half maximum (FWHM) and photoluminescence quantum yield (PLQY) of the emission spectrum. The ZnSe intermediate shell plays a crucial role in removing lattice mismatches. This study reveals the optimum thickness range and the negative effects of electron delocalization at excessive thicknesses.

Abstract

Multi-shell InP/ZnSe/ZnS quantum dots (QDs) are expected to be applied to next-generation displays. While the effect of the thickness of the ZnSe intermediate shell on the properties of InP/ZnSe/ZnS QDs has been reported for red-emission, there are few reports on green-emitting ones. Here we show the effects of ZnSe thickness on full width at half maximum (FWHM) and photoluminescence quantum yield (PLQY) of the emission spectra of green-emitting InP/ZnSe/ZnS QDs. The results revealed that the ZnSe intermediate shell of green-emitting InP/ZnSe/ZnS QDs has an optimum thickness (1.2 nm in this study). Excessive or insufficient ZnSe intermediate shell broadened FWHM and decreased PLQY. This means that difference in the thickness of the ZnSe intermediate shell changes the band structure and the electron behavior. The ZnSe thickness is one of the dominant factors that determine the optical properties in green-emitting InP/ZnSe/ZnS QDs.

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