Preparation and nonlinear optical characterization of Flourine-doped cadmium oxide thin films

Abstract

Undoped CdO films and three different molarities of cadmium oxide (CdO) films were doped with fluorine on glass slides via a chemical spray pyrolysis method. The samples were analyzed using X-ray diffractometry (XRD), scanning electron microscopy (SEM), UV–VIS-NIR spectroscopy, electrical measurements, and Z-scan measurements. XRD measurement revealed better crystallinity with preferred orientation at [111] plane. Nanospheres of varying sizes were obtained from the surface micrographs. The direct band gap energy decreased as the fluorine concentration increased. The film resistivity recorded a decline with increased carrier mobility as the flourine concentration increased. The nonlinear optical absorption coefficient (β) gotten for 0.0003 M, 0.0004 M, and 0.0005 M at 632.8 nm wavelength are 3.83×10–3 m/W, 5.7 × 10–3 m/W and 5.48×10–3 m/W respectively. The deposited films find potential application in solar cell and optoelectronic devices.

Keywords

• Thin film
• CdO:F
• Spray pyrolysis
• XRD
• Band gap energy
• Z-scan