Significance of the nano-shapes in nanoparticle-enhanced laser-induced breakdown spectroscopy
The role played by the shape of the nanoparticles on the nanoparticle-enhanced LIBS (NELIBS) signal should be clarified. The present study reports on the effect of silver (silver chloride) nanoparticles shape (nanospheres, nanocubes, and nanowires) on the LIBS signal for different target materials; two metals (aluminum and zinc), and one semiconductor (silicon). The shape enhancement factor and the plasma parameters, namely plasma temperature, and electron density, have also been evaluated. Silver nanoparticles have been characterized using different techniques, including SEM, UV-vis, and XRD. Results showed that the clusters formed in the silver nanowires and nanocubes play an essential role in the laser pulse's absorption mechanism and, consequently, enhance the LIBS signal. Nanowires followed by nanocubes showed better enhancement than nanospheres, confirmed by the shape-dependent enhancement factor. However, the laser-induced plasma parameters (plasma temperature and electron density) have not been affected much with the nano-shape change.