Sol-Gel Synthesis of Aluminum Doped CdO Thin Films for Optoelectronic Applications


MATERIALS FOCUS, vol.7, no.1, pp.126-131, 2018 (Peer-Reviewed Journal) identifier

  • Publication Type: Article / Article
  • Volume: 7 Issue: 1
  • Publication Date: 2018
  • Doi Number: 10.1166/mat.2018.1489
  • Journal Name: MATERIALS FOCUS
  • Page Numbers: pp.126-131
  • Eskisehir Osmangazi University Affiliated: Yes


Aluminum-doped transparent and conductive cadmium oxide (CdO: Al) thin films were deposited by the sol-gel technique onto indium tin oxide (ITO) glass substrates using dip coating method. The deposition used cadmium acetate solutions of 0.3 M in 2-methoxyethanol stabilized by monoethanolamine and doped with Al. XRD results showed that a polycrystalline phase with a cubic crystal structure with (111) preferred orientation but doping with high Al concentrations (20 wt%) leads to the formation of XRD-amorphous films. The values of structural parameters (such as grain size, lattice parameter, dislocation density, texture coefficient) were found to be varying with the Al concentration. Grain size calculations based on XRD analysis revealed that all the films were nanocrystalline in nature consisting of quantum dots with sizes ranging from 23-30 nm. SEM micrographs showed that the surface morphology of the films was affected from the Al incorporation. The direct band gap energy values decreased from 2.99 for undoped CdO to 2.53 eV for 20 wt% Al doped CdO. The lowest resistivity of about 3.2x10(-4) Omega cm was measured for 10 wt% Al-doped CdO film. Films with an average optical transmittance exceeding 80% were achieved.