Resumo

ASOGWA, P.U.; EZUGWU, S.C.  e  EZEMA, F.I.. Variation of optical and solid state properties with post deposition annealing in PVA-Capped MnO₂ thin films. Superf. vacío [online]. 2010, vol.23, n.1, pp.18-22. ISSN 1665-3521.

MnO₂ thin films were synthesized on glass substrate by chemical bath deposition technique within the pores of polyvinyl alcohol (PVA) at room temperature. The chemical bath for the deposition of MnO₂ is made up of solution of MnCl₄, NH₄Cl, NH₃, and PVA solution. The deposited films were annealed in air at 473K and 673K and characterized for the structural, morphological and optical properties. These properties were studied by means of X-ray diffraction (XRD), optical microscopy and optical spectrophotometer for their potential application in solar energy devices. From the absorption spectra, the calculated direct and indirect band gap energies lie respectively in the range of 1.8 - 2.5 eV and 0.8 and 1.2 eV. The films show good transmittance in the near infrared region of the solar spectrum. Post deposition annealing affects both the optical and solid state properties of the films.

Palavras-chave : Chemical bulk deposition; Transparent semiconductor; Oxides thin films.