ZnSTe/ZnSe/ZnS core/shell/shell quantum dots (QDs) were fabricated using a single ZnS precursor to achieve blue-emitting QDs at 450 nm. In this structure, a small quantity of tellurium (Te) was surface-doped on the inner-core ZnS surface, positioned at the interface with the ZnSe shell. This doping suppressed surface trap emission and induced red-shifted emission in the final ZnSTe/ZnSe/ZnS core/shell/shell QDs, resulting in an improved quantum yield (QY) when the final ZnS shell was applied. These QDs showed a photoluminescence (PL) wavelength of 447 nm, FWHM of 35 nm, and QY of 74%. They exhibited superior symmetry in emission spectrum. The symmetry of the emission at half-maxima indicated 17.3 nm and 18.2 nm on either side of the peak center. When utilized in electroluminescent devices (ELs), quantum-dot light-emitting diodes (QLEDs) demonstrate a band-edge emission with symmetric EL spectra centered at λmax of 451 nm, with a full width at half maximum (FWHM) of 30 nm. They achieve a maximum luminance of 2,200 cd/m², an external quantum efficiency of 4.58%, and a current efficiency of 2.31 cd/A.
