Determination of Film Thickness and Element Content Dependence for Laser-Induced Breakdown Spectroscopy (LIBS) of an AlZnO Film
D-Q. Yuan, M. Zhou and J-T. Xu
Laser-induced breakdown spectroscopy (LIBS) is gaining popularity as a technique for solid sample characterization. The emission from a laser-induced plasma of several Al(I) and Zn(I) spectral lines had been studied to investigate the influence of the delay time, pulse energy, concentration of elements and the thickness of the film on the line intensity. The plasma was generated using a Q-switched Nd: YAG laser emitting a 10 ns pulse at a wavelength of 1064 nm to irradiate the surface of an AlZnO film in air at atmospheric pressure. The plasma emission spectroscopy was detected with linear charge-coupled device (CCD) array through a bundle of seven optical fibres, each with a diameter of around 600 μm. After calculating the temperature of excited plasma we found that it could be divided into two regions depending upon the pulse energy. Also, the intensity of the emission lines could be divided into two regions depending on the pulse energy. Finally, we investigated the effect of element concentration and the thickness of film on signal intensity.
Keywords: Nd:YAG laser, AlZnO film, laser-induced breakdown spectroscopy (LIBS), plasma temperature, spectroscopy