Photoluminescence analysis of colloidal silicon nanoparticles in ethanol produced by double-pulse ns laser ablation

Silicon nanoparticles (SiNPs) have attracted much attention for optoelectronic devices as well as biomedical applications due to their wide range of visible emissions, which are greatly influenced by their surface characteristics. This paper presents photoluminescence properties of colloidal SiNPs produced by using single-pulse and double-pulse nanosecond laser ablation of silicon in ethanol. The laser ablation processes were performed under the same experimental conditions, but the experiments result in production of the colloidal SiNPs with different size and surface characteristics. The structural and optical properties of colloidal SiNPs were investigated, with the aim of clarifying the role of surface characteristics on the photoluminescence emissions. The SiNP colloids exhibit similar luminescence behavior to the pure ethanol at the spectral range of 300-600 nm, with a slight enhancement of intensity. The results indicate that the excitation-dependent photoluminescence spectra of the colloids are associated with the Raman scattering of pure ethanol which are enhanced due to the presence of SiNPs with different OH related surface characteristics.