Non-injection synthesis of doped zinc oxide plasmonic nanocrystals

Plasmonic metal oxide nanocrystals bridge the optoelectronic gap between semiconductors and metals. In this study, we report a facile, non-injection synthesis of ZnO nanocrystals doped with Al, Ga, or In. The reaction readily permits dopant/zinc atomic ratios of over 15%, is amenable to high precursor concentrations (0.2 M and greater), and provides high reaction yields (>90%). The resulting colloidal dispersions exhibit high transparency in the visible spectrum and a wavelength-tunable infrared absorption, which arises from a dopant-induced surface plasmon resonance. Through a detailed investigation of reaction parameters, the reaction mechanism is fully characterized and correlated to the optical properties of the synthesized nanocrystals. The distinctive optical features of these doped nanocrystals are shown to be readily harnessed within thin films that are suitable for optoelectronic applications.