Laser induced breakdown optical emission spectroscopic study of silicon plasma.

Abstract

The laser induced breakdown optical emission spectroscopy technique has been employed for the analysis of silicon sample in the atmospheric air. Laser irradiance of 1 × 1011 Wcm-2 was created on specimen of silicon sample surface to generate the plasma plume by using the fundamental of Nd:YAG laser pulse. This laser produced silicon plasma was captured through the LIBS 2000 Spectrometer for the subsequent analysis of silicon sample. The electron temperature of silicon plasma is estimated to be 7500 K to 4000 K while electron number density of silicon plasma lies 3.2 × 1017 to 1.8 × 1017. In spatially resolved laser induced plasma and this temperature of silicon plasma has been estimated from the Boltzmann plot method to be in local thermodynamic equilibrium, and electron number density of silicon plasma has been estimated from the Stark width broadening at λ ~ 288.1 nm respectively. Observed result in spatially resolved laser plasma which shows the recombination rate of plasma plume along the direction of expansion. Which also affects on the temperature and density of silicon plasma besides the intensity decreasing factor with distance in silicon ionic and neutrals transition lines is discussed.