Synthesis and modification of Cu-C70 nanocomposite for plasmonic applications

• Published in: Applied surface science 2019-02, Vol.466, p.615-627
• Main Authors: Singhal, Rahul, Gupta, Satakshi, Vishnoi, Ritu, Sharma, Ganesh D.
• Format: Article
• Language: English
• Subjects: Fullerenes; Low energy ion irradiation; Noble metal nanoparticles; Surface plasmon resonance
• ISSN: 0169-4332; 1873-5584
• DOI: 10.1016/j.apsusc.2018.10.029

[Display omitted] •Red and blue shift of SPR wavelength through low energy ion irradiation.•Transformation of fullerene into amorphous carbon.•Breaking of sp3 bonds and its conversion to sp2 bonds.•Growth of copper nanoparticles with increasing fluence.•Enhancement in the conductivity of Cu-C70 nanocomposite with irradiation. Low energy ion irradiation is an interesting tool to accomplish the bulk modifications of different materials. The impact of low energy ion bombardment is studied on Cu-C70 nanocomposite thin films prepared by thermal co-deposition technique. A beam of 180 keV Ar ions was used for this purpose which results in a drastic change in structural, optical and electrical properties. It is demonstrated that surface plasmon resonance (SPR) was successfully induced with ion irradiation initially at a fluence of 3 × 1014 ions cm−2 and is observed to be first red shifted and then blue shifted on increasing fluence of ion irradiation. The results of Raman spectroscopy reveal the progressive transformation of fullerene C70 into amorphous carbon with increasing fluence. The I(D)/I(G) ratio is calculated to analyze amorphous carbon and improved ordering of amorphous carbon at higher fluences is observed. TEM images verified the continuous growth of copper nanoparticles subjected to low energy ion irradiation with increasing fluence which is ascribed to the agglomeration of particles as pointed by EDS mapping images. FTIR results show that the destruction of fullerene C70 matrix is initiated at a fluence of 3 × 1014 ions cm−2, which coincides with the appearance of SPR band. The transformation of fullerene into amorphous carbon and the growth of copper nanoparticles was found to be responsible for increase in conductivity with fluences as confirmed by I-V measurements.