Luminescent properties of colloidal mixtures of Zn0.5Cd0.5S quantum dots and gold nanoparticles

Abstract

The aim of the study is to establish spectral-luminescent interaction effects in mixtures of colloidal Zn0.5Cd0.5S quantum dots passivated with 2-mercaptopropionic acid and Au and Au/SiO2 nanoparticles. The studied samples of Zn0.5Cd0.5S quantum dots, Au and Au/SiO2 nanoparticles and their mixtures were obtained by methods of colloidal synthesis and were characterised using transmission electron microscopy. The absorption, luminescence and time-resolved luminescence spectroscopy were used as the main investigation methods. The measurements were carried out at temperatures of 77 K and 300 K. The spectral-luminescent properties of “free” Zn0.5Cd0.5S quantum dots and those interacting with Au and Au/SiO2 nanoparticles were compared. It was found that the luminescence properties of Zn0.5Cd0.5S quantum dots can be controlled under conditions of changing plasmon-exciton coupling achieved during the formation of a dielectric SiO2 shell on the surface of Au nanoparticles as well as a result of a polymer introduced into the colloidal mixture.

Keywords

• zn0.5cd0.5s quantum dots
• gold nanoparticles
• core/shell
• silicon dioxide (sio2 )
• extinction spectrum
• plasmon
• exciton interaction