Growth ambient dependence of defects, structural disorder and photoluminescence in SnO2 films deposited by reactive magnetron sputtering

• Published in: Journal of alloys and compounds Vol. 583; pp. 186 - 190
• Main Authors: Bansal, Shikha, Pandya, D.K., Kashyap, Subhash C., Haranath, D.
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier B.V 2014; Elsevier
• Subjects: Condensed matter: electronic structure, electrical, magnetic, and optical properties; Defects; Disorders; Electrical properties; Emission; Exact sciences and technology; Flow rate; Magnetron sputtering; Optical band gap; Optical properties and condensed-matter spectroscopy and other interactions of matter with particles and radiation; Optical properties of specific thin films; Photoluminescence; Physics; Reactive sputtering; SnO2 thin films; Tin dioxide; Tin oxides; Urbach tail width; Optical band gap; Reactive sputtering; SnO2 thin films; Electrical properties; Urbach tail width; Photoluminescence; Crystal defects; Transparency; Electrical conductivity; Vacancies; Interstitials; Fabrication property relation; Nonstoichiometry; Thin films; Ultraviolet radiation; Partial pressure; SnO; Tin oxide; Urbach rule; Carrier density
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/j.jallcom.2013.08.135

•Oxygen vacancy control by means of oxygen flow rate.•Optical properties are affected by change in microstructure of the films.•Reduction in structural disorder with increase in oxygen flow rate.•PL characteristics have been ascribed to the presence of intrinsic defects.•A high band gap of 4.01eV is obtained at a lower oxygen flow rate. The present paper deals with the study of photoluminescence (PL) and the other physical properties (structural, electrical and optical) of SnO2 thin films with controlled disorder and intrinsic defects induced during the reactive magnetron sputtering by changing oxygen flow rate from 12 to 16sccm. The changes in unit cell volume, near band-edge optical transparency and width of Urbach tail in the films are correlated with the structural disorder and presence of intrinsic defects induced by growth under different oxygen partial pressures. The increased intensity of the PL near UV emission and decrease in the intensity of visible emission peaks with increase in oxygen flow rate is linked with the decrease in oxygen vacancies and tin interstitials in the films. With increasing oxygen content, whereas the electrical resistivity of the films minimizes to a value of 4.3×10−2ohm cm at 14sccm, the mobility of the films increases to a saturation value 15cm2V−1s−1. The donor-defect concentration linked carrier density is observed to decrease monotonically from 2×1019 to 0.6×1019cm−3.