Out-diffused silver island films for surface-enhanced Raman scattering protected with TiO2 films using atomic layer deposition
1 Institute of Photonics, University of Eastern Finland, P.O. Box 111, Joensuu FI-80101, Finland
2 Institute of Physics, Nanotechnology and Telecommunications, St. Petersburg State Polytechnic University, 29 Polytechnicheskaya, St. Petersburg 195251, Russia
3 Ioffe Physical-Technical Institute of the RAS, 26 Polytekhnicheskaya, St. Petersburg 194021, Russia
4 Department of Physics and Technology of Nanostructures, St. Petersburg Academic University, 8/3 Khlopina, St. Petersburg 194021, Russia
Nanoscale Research Letters 2014, 9:398 doi:10.1186/1556-276X-9-398Published: 15 August 2014
We fabricated self-assembled silver nanoisland films using a recently developed technique based on out-diffusion of silver from an ion-exchanged glass substrate in reducing atmosphere. We demonstrate that the position of the surface plasmon resonance of the films depends on the conditions of the film growth. The resonance can be gradually shifted up to 100 nm towards longer wavelengths by using atomic layer deposition of titania, from 3 to 100 nm in thickness, upon the film. Examination of the nanoisland films in surface-enhanced Raman spectrometry showed that, in spite of a drop of the surface-enhanced Raman spectroscopy (SERS) signal after the titania spacer deposition, the Raman signal can be observed with spacers up to 7 nm in thickness. Denser nanoisland films show slower decay of the SERS signal with the increase in spacer thickness.
78.67.Sc (nanoaggregates; nanocomposites); 81.16.Dn (self-assembly); 74.25.nd (Raman and optical spectroscopy)