Blue–green luminescent CdZnSeS nanocrystals synthesized with activated alkyl thiol

Semiconductor nanocrystals with blue–green luminescence are potentially useful in various applications, but the preparation has not been easy compared to regular semiconductor nanocrystals with emission in the orange–red range. In this research alloyed CdZnSeS nanocrystals with luminescence covering the wavelength range from 430 to 560 nm are obtained by a one-step method with the assistance of alkyl thiol compound 1-dodecanethiol, which serves both as the sulfur source and surface ligand. The luminescence of CdZnSeS nanocrystals can be tuned from blue to green by altering the Cd:Zn molar ratio. Besides, the amount of 1-dodecanethiol in the reaction mixture can influence the emission wavelength by restricting the growth of nanocrystals. The dual control of both particle composition and size has enabled the tuning of luminescence to cover the blue–green spectral window. This research presents a convenient method to synthesize nanocrystals with tunable blue–green emission; these materials can be useful in advanced technologies such as photovoltaics, lighting and display.