Stokes-shift engineered CdSe/CdS/Cd1-xZnxSe1-ySy nanoplatelets with tunable emission wavelength

Abstract

A facile synthetic route to preparing CdSe/CdS/Cd1-xZnxSe1-ySy core/shell/shell nanoplatelets (NPLs) was introduced via a sequential passivation of plain CdSe NPLs with CdS and Cd1-xZnxSe1-ySy shell. The CdS/Cd1-xZnxSe1-ySy shell was passivated by 1-dodecanethiol and cadmium oleate and zinc oleate precursors by capitalizing on their chemical reactivity difference. Red-shift of the absorption and emission positions of prepared CdSe/CdS/Cd1-xZnxSe1-ySy NPLs was observed due to the delocalization of electron in the shell. Resulting core/shell NPLs exhibited large Stokes’ shift which can possibly reduce re-absorption. Core/shell/shell NPLs exhibited excellent photo-stability compared to plain CdSe NPLs. Photoluminescence decays of resulting core/shell NPLs was studied. The shape and size of NPLs was characterized using high-resolution transmission electron microscope. © 2022 Elsevier B.V.