Influence of deposition pressure on N-doped ZnO films by RF magnetron sputtering.
N-doped ZnO films were deposited on glass substrates by RF magnetron sputtering with different deposition pressures. The samples were characterized by X-ray diffraction (XRD), atomic force morphology (AFM), X-ray photoelectron spectroscopy (XPS), Hall measurements and optical spectrophotometer. The XRD patterns confirmed that the films are polycrystalline and the influence of deposition pressure on the structural properties. AFM microstructures also authenticated the change in the size and shape of the grains as a function of deposition pressure; the root mean square (RMS) roughness has reached a maximum (10.65 nm) at 1.5 x 10(-2) mbar. XPS spectra revealed the change in the chemical composition. The amount of adsorbed oxygen and nitrogen at oxide sites has reached the maximum at 9.0 x 10(-3) mbar, where the film showed p-type conductivity. The optical transmittance spectra have indicated that the absorption edge is shifted towards the shorter wavelength at higher deposition pressure. Correspondingly, the optical band gap is increased from 2.17 to 2.80 eV. The average visible transmittance in the wavelength ranging 500-800 nm has been increased from 49% to 82%.
Wang
Jinzhong
J
Material Science Department, CENIMAT/13N and CEMOP/UNINOVA, FCT-UNL, Campus de Caparica, 2829-516 Caparica, Portugal.
Elamurugu
Elangovan
E
Franco
Nuno
N
Alves
Eduardo
E
Botelho do Rego
Ana M
AM
Gonçalves
Gonçalo
G
Martins
Rodrigo
R
Fortunato
Elvira
E