New, epitaxial approach to SERS platform preparation – InP nanowires coated by an Au layer as a new, highly active, and stable SERS platform

Abstract

The deposition of a plasmonic metal layer on a highly ordered, nanostructured semiconducting layer is an important method of SERS platform preparation. In this contribution to the best of our knowledge, we will describe for the first time a highly ordered InP nanowire surface coated by an Au layer as a highly efficient and stable SERS platform. The influence of various factors affecting InP nanowire growth have been studied and the structural and optical properties examined. The SERS measurements showed very high SERS enhancement factors for the InP@Au SERS platforms produced. The calculated SERS enhancement factor for the InP nanowires covered with ca. 220 nm thick layer of Au was 2.3∙106, which is one of the highest SERS enhancement factors for the gold-based SERS platforms so far. The studied samples exhibit high repeatability from point to point measurement, lower than 10 % RSD. Additionally, there was no decrease in the measured intensity of the SERS spectra in time, even after 3 months.