Effects of Grain Size on the UV‐Photoresponse of Zinc Oxide Thin Films Grown by Spray‐Pyrolysis. Issue 11 (26th April 2018)

• Record Type: Journal Article
• Authors: Villegas, Edgar A.; Aldao, Celso M.; Savu, Raluca; Ramajo, Leandro A.; Parra, Rodrigo
• Is Part Of: Physica status solidi. Volume 215:Issue 11(2018)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2018-04-26
• Subjects: spray‐pyrolysis -- thin films -- ultraviolet photodetectors -- zinc oxide; Solid state physics -- Periodicals; Solids -- Industrial applications -- Periodicals; 530.41
• DOI: 10.1002/pssa.201800107
• Languages: English
• ISSNs: 1862-6300

Abstract

Abstract : Zinc oxide films with different average grain size are deposited on glass substrates by spray‐pyrolysis at 425 °C. Samples are characterized by XRD, UV–Vis transmittance, FE‐SEM, and electrical properties measurements. The increase in conductivity observed under 365 nm wavelength illumination is evaluated in terms of grain size. Films with small grains (120 nm) show higher response with respect to films with larger grains (230 and 300 nm). A model considering resistivity and grain size for the prediction of the response of films in terms of UV‐to‐dark conductivity ratio is proposed and validated with experimental results. Abstract : Modifications in the spraying conditions led to zinc oxide films with interesting changes in grain size and morphology. Grains evolved from hexagonal platelets to 3D stacked‐platelet grains by spraying growing solution volumes. Films with small grains shows the highest UV‐to‐dark conductivity ratio. This behavior is reproduced by a simple physical model with grain size and film resistivity as main entries.