Optical properties of silicon nanoparticles synthesised at different heating rates via physical vapour condensation method

Abstract

A physical vapour condensation method is employed to fabricate the silicon nanoparticles at different heating rates. We have grown silicon nanoparticles at two different heating rates i.e., 10°C/min and 20°C/min. It is observed that the nanoparticles synthesise at low heating rate (10°C/min) are more uniform and spherical with size varying between 10nm to 40 nm. The average surface roughness is about 160 nm as evident from the AFM images. Whereas, the silicon nanoparticles grown at higher heating rate i.e., 20°C/min looks like aggregated and appears as nanoclusters. The size of these nanoparticles varies between 5 nm to 10 nm and the average surface roughness is about 140 nm. The photoluminescence (PL) observed from silicon (Si) nanoparticles has been explained with the help of oxygen-related surface state mechanism.