Synthesis of bright photostable red luminescent Cu nanoparticles

Abstract

We have synthesised luminescent copper nanoparticles directly on a silicon wafer using a low cost electrochemical deposition process. The nanoparticles exhibit strong red luminescence under UV or blue excitation. The synthesised nanomaterial was characterised using normal/fluorescent microscopy, UV-visible and Fourier transform infrared spectroscopy, and X-ray diffraction patterns. The results demonstrated non-bulk luminescent characteristics and partial oxidation of the synthesised nanomaterial. Direct imaging of the extracted material using transmission electron microscopy demonstrated the production of agglomerated copper nanoparticles with an estimated average size 10–30 nm. The synthesised nanomaterial demonstrated high photostability against prolonged excitation and/or atmospheric exposure. We interpret the results in terms of a model in which copper nanoparticles were formed via electrodeposition on the polished silicon surface with subsequent nucleation process that lead to the formation of agglomerates of the nanoparticles. The agglomerates have different shapes and size, but with an average size of 10–30 nm.