Optical and thermal characterization of pure CuO and Zn/CuO using laser-induced breakdown spectroscopy (LIBS), x-ray fluorescence (XRF), and ultraviolet–visible (UV–Vis) spectroscopy techniques

Abstract

We present elemental analysis and thermal characterization of pure and two different concentrations of zinc-doped copper oxide (CuO) samples using different analytical techniques. The quantitative as well as qualitative investigations, were performed by incorporating calibration-free laser-induced breakdown spectroscopy (CF-LIBS) technique. The plasma was generated on the samples surface by focusing a first harmonic of Nd: YAG laser of 1064 nm wavelength and the time-integrated emission spectra was achieved through a set of five spectrometers equipped with a charge-coupled-device. The acquired optical emission spectra from laser-generated plasma show different concentrations of zinc and copper in different samples which are consistent with their percentage composition measured during the sample synthesis. Using LIBS emission analytical lines, the Boltzmann technique was utilized for estimating the excitation temperature, while the number density was evaluated using the well-known Stark broadening line profile method. Besides, the CF-LIBS elemental analysis was validated by the x-ray fluorescence technique. For the optical study, ultraviolet–visible spectroscopical analysis was performed to find the bandgap of pure and zinc-doped copper oxide samples and consequently, variation in bandgap was studied with the growth of zinc doping. In addition, the thermal properties of the samples were analyzed using the beam deflection spectroscopy technique. The results shows that thermal diffusivity () and thermal conductivity (), increased with an increase in zinc concentration.