Pressure effeect on optical and structural properties of ZnMnO thin films grown by pulsed laser deposition

J. D. LOPEZ; K .L. SALCEDO ; H. RIASCOS

Bariloche

Simposio; XXIII Latin American Symposium on Solid State Physics; 2018

Centro Atomico Bariloche

Zn&_{0,95}$Mn$_{0,05}$O thin films with different pressure were deposited on Si substrate by pulsed laser ablation technique, through a pulsed laser (1064 nm, and 9 ns) under oxygen atmosphere and average energy around 100 mJ per shot. The structural and optical properties of the films were analyzed as a function of the oxygen gas pressure. The Mn concentration in the films was around 5% Wt, the grown process was carried out at a substrate temperature of 473 K. The crystalline structure of the samples was investigated using X-ray diffraction technique (XRD) and Atomic Force Spectroscopy (AFM). Raman Spectroscopy and UvVis were employed to characterize the optical properties of the films. The diffraction patterns revealed that the ZnMnO thin films were polycrystalline and have a wurtzite hexagonal structure of ZnO and without any second phases. XRD pattern of the Mn doped ZnO shows the presence of strong intensity peak arising (002) reflection, indicating that the highly c-axis oriented film grown. A lightly shift in peak positions towards lower 2è values has been observed, which may be due to the incorporation of Mn ions inside the ZnO crystal lattice. Some important structural parameters (lattice parameters of the hexagonal cell, crystallite size, tensile and compressive stress) of the films were determined. The dependence of the optical characteristics on the preparation conditions, using a UV-VIS spectrophotometer, was discussed. The average energy band gap of the films was evaluated around 3.23-5.56 eV. Raman spectrum shows E2 (low) mode of ZnO structure shifted to red and increasing its FWHM. Also was observed E2 (high) mode which is ZnO wurtzite structural related.