Synthesis and optical properties of Janus structural ZnO/Au nanocomposites
State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University Nanjing 210096, China
Received: 28 March 2014
Accepted: 23 May 2014
Zinc oxide quantum dot (ZnO QD)/gold nanoparticle (Au NP) nanocomposites with Janus structure were synthesized through a bridge linking of 3-mercaptopropionic acid (3MPA). The bare ZnO QDs presented a typically weak inherent ultraviolet (UV) emission band and a strong defect-related visible band. After Au NPs were assembled onto the surfaces of ZnO QDs, the ZnO/Au nanocomposites exhibited a dramatic enhancement of UV emission and quenching of visible emission. It was noted that the defect emission of ZnO QDs matched with the localized surface plasmon resonance (LSPR) peak of Au NPs, which resulted in a LSPR-assisted electron transfer process from Au NPs to ZnO QDs, so the defect emission was suppressed. The LSPR-assisted electron transfer process was confirmed by the time-resolved photoluminescence.
PACS: 73.40.Qv – Metal-insulator-semiconductor structures (including semiconductor-to-insulator) / 52.25.Tx – Emission, absorption, and scattering of particles / 73.63.Rt – Nanoscale contacts
© EPLA, 2014