Effect of heat treatment on the NO2-sensing properties of sputter-deposited indium tin oxide thin films

• Published in: Philosophical magazine letters Vol. 91; no. 10; pp. 682 - 689
• Main Authors: Vijayalakshmi, K., Pillay, Vasanthi V.
• Format: Journal Article
• Language: English
• Published: Abingdon Taylor & Francis Group 01.10.2011; Taylor & Francis
• Subjects: Annealing; Conduction; Cross-disciplinary physics: materials science; rheology; Crystal structure; Deposition; Deposition by sputtering; Electrical properties; Electrical resistivity; Exact sciences and technology; General equipment and techniques; Indium tin oxide; Instruments, apparatus, components and techniques common to several branches of physics and astronomy; ITO film; Materials science; Methods of deposition of films and coatings; film growth and epitaxy; nanostructures; Physics; sensor; Sensors (chemical, optical, electrical, movement, gas, etc.); remote sensing; sputtering; Thin films; Vapor phase epitaxy; growth from vapor phase; Scanning electron microscopy; Annealing; Electrical conductivity; Electrical properties; Surface morphology; Crystallinity; Coatings; Indium oxide; Heat treatments; Thin films; Partial pressure; Tin oxide; Physical vapor deposition; Electric resistivity; Surface area; Nitrogen dioxide
• ISSN: 0950-0839; 1362-3036
• DOI: 10.1080/09500839.2011.608731

Transparent conducting indium tin oxide (ITO) films were deposited onto glass substrates by radio-frequency magnetron sputtering at 648 K, under an oxygen partial pressure of 1 Pa. The effect of annealing on the electrical properties of the films was studied. Characterization of the coatings revealed an electrical resistivity below 6.5 × 10 − 3  Ω cm. The ITO films deposited at 648 K were amorphous, while the crystallinity improved after annealing at 700 K. The surface morphology examined by scanning electron microscopy appears to be uniform over the entire surface area after annealing. The NO 2 -sensing properties of the ITO films were investigated and showed sensitivity at concentrations lower than 50 ppm, at a working temperature of 600 K.