Opto-electronic properties of Co-Zn-Ni-O films deposited by RF-sputtering at ambient-temperature

• Published in: Journal of alloys and compounds Vol. 801; no. C; pp. 409 - 414
• Main Authors: Ford, J.C., Zakutayev, A., Ndione, P.F., Sigdel, A.K., Widjonarko, N.E., Parilla, P.A., Van Zeghbroeck, B., Berry, J.J., Ginley, D.S., Perkins, J.D.
• Format: Journal Article
• Language: English
• Published: Lausanne Elsevier B.V 15-09-2019; Elsevier BV; Elsevier
• Subjects: Ambient temperature; CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; Cobalt oxides; Composition; Crystal structure; Domains; Electrical resistivity; Electrical transport; Electronic properties; MATERIALS SCIENCE; Optical properties; Optoelectronics; Oxide materials; P-type semiconductors; Sputtering; Substrates; Thin films; Vapor deposition; Work functions; Wurtzite; Zinc oxide; Thin films; Vapor deposition; Oxide materials; Electrical transport; Optical properties; Crystal structure
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/j.jallcom.2019.05.275

Co-Zn-Ni-O thin films were grown on glass at ambient temperature (TS < 65 °C) by co-sputtering from Co3O4, ZnO, and NiO targets to determine the structural and opto-electronic properties across the ternary composition space. Compositional domains with spinel, wurtzite, rock-salt, and mixed phases were observed, albeit with very weak X-ray diffraction peaks, overall suggesting the likely presence of a co-existent amorphous component. The electrical conductivity had a maximum value of ∼35 S/cm that occurs where the optical absorption is also the strongest. The work functions range from 5.0 to 5.8 eV for all samples, but with no clear composition-based trends. Overall, it appears that the optoelectronic properties of the Co-Zn-Ni-O materials are much less sensitive to substrate temperature compared to other p-type oxide semiconductors, resulting in technologically-relevant ambient-temperature-deposited thin films.
•Majority of pseudo-ternary CoO-NiO-ZnO composition space explored.•Co-Zn-Ni-O conductivity depends less on temperature than other p-type oxides.•Ambient-temp-deposited Co-Zn-Ni-O films have technologically relevant conductivity.•For Ambient-temp-deposited Co-Zn-Ni-O, highest conductivity films are the least crystalline.