Laser-induced silicon nanocolumns by ablation technique

Abstract

High-purity silicon wafers were irradiated in ultrapure water environment by laser ablation (LA). Columnar structures were induced on the surface using multiple pulses from Nd:YAG laser. Nd:YAG pulsed laser irradiance with 1.3 × 109 W/cm2 operated at 266 nm wavelength, 6 ns pulse duration, and 10 mJ pulse energy with different repetition rates 10 Hz and 20 Hz. Shape, structure, and size distribution of silicon nanocolumns were determined by scanning electron microscope and particle counting method. High populations of silicon nanoparticles were formed on the surfaces of the substrates after LA process. Elemental composition analysis was performed by energy dispersive x-ray spectrometer for the silicon targets and the deposited nanoparticles. Surface area of the silicon nanoparticles was measured by gas sorption process. UV-Visible spectrophotometer was used to detect the scattered light from the nanocolumns structure on the silicon target.