Morphology and photoluminescence properties of silicon nanoparticles deposited in helium-nitrogen mixtures maintained at low residual pressures

Abstract We elaborated a technique of pulsed laser ablation in gas mixtures (He-N 2 ), maintained under residual pressures 0.5–5 Torr to deposit silicon (Si)-based nanostructured films on substrate. show that the deposited can exhibit strong photoluminescence (PL) emission with position peaks depending pressure ambient and ratio gases mixture. Nanostructured prepared pure He exhibited band infrared range (around 760 nm) weak green (550 nm), which were attributed quantum-confined excitonic states small Si nanocrystals radiative transitions via localized electronic suboxide coating, respectively. In contrast, He-N more intense “green-yellow” PL centered at 580 nm, was recombination amorphous oxynitride (a-SiN x O y ) coating nanocrystals. also present detailed analysis morphology nanostructures Si-based by ablation. Finally, we be removed from substrate milled ultrasound form aqueous solutions colloidal nanopartiles. The fabricated promising object for theranostics, combining imaging functionality based series therapy functionalities (photo radiofrequency hyperthermia, photodynamic therapy).