Structural and optical study of Li doped CuO thin films on Si (1Â 0Â 0) substrate deposited by pulsed laser deposition

In the present study, we report structural and optical properties of Cu1 − xLixO thin films grown on Si (1 0 0) substrates by pulsed laser deposition at different doping concentrations (x = 0.0, 0.05, 0.07 and 0.09). The XRD spectra indicates the formation of polycrystalline CuO thin films and the crystallite size, calculated through XRD data is found to be increased from 7 to 14 nm for the samples with x = 0 to 0.09, respectively. FESEM analysis shows that the average size of Cu1 − xLixO nanostructures increases from 47 to 97 nm and AFM analysis also shows that the average size of Cu1 − xLixO nanostructures increases from 35 to 79 nm by increasing the Li doping concentrations from x = 0 to 0.09, respectively. Energy dispersive X-ray analysis with elemental mapping of the Li-doped CuO thin films shows that the Li dopants are incorporated homogeneously into the CuO thin film matrix. Moreover, Raman and photoluminescence spectra also confirm the single-phase formation of CuO thin films. A significant reduction in optical energy band gap is observed from 2.99 to 2.76 eV with an increase of Li concentration from 0 to 9%, respectively.