Structure and Optical Properties of Transparent Cobalt-Doped ZnO Thin Layers

Transparent thin layers of cobalt-doped ZnO were produced with the pulsed laser deposition method. The cobalt content original solid solution was 20% at. crystallographic structure examined by X-ray diffraction, which showed that fabricated crystallized in wurtzite phase and had a dominant orientation along a-axis. texture coefficient (increasing from F = 0.08 for non-annealed layer to 0.94 annealed at 400 °C) grain size (D 110 ÷ 140 nm) calculated. Optical constants, such as refractive index n (1.62) extinction k (0.1 0.4), determined ultraviolet–visible–near-infrared transmission spectrum using envelope value optical band gap determined, is lower than pure ZnO. Increasing annealing temperature ZnO:Co increases Urbach energy 0.20 0.25 eV, shows difference type growth defects matrix.