Local Structure and Surface Properties of CoxZn1-xO Thin Films for Ozone Gas Sensing

Author(s)

Catto, Ariadne C. ; da Silva, Luis F. ; Bernardi, Maria Ines B. ; Bernardini, Sandrine ; Aguir, Khalifa ; Longo, Elson ; Mastelaro, Valmor R.

• Document type: Journal article
• Source: ACS APPLIED MATERIALS & INTERFACES; v. 8, n. 39, p. 26066-26072, OCT 5 2016.
• Web of Science Citations: 21

Abstract

A detailed study of the structural, surface, and gas-sensing properties of nanostructured CoxZn1-xO films is presented. X-ray diffraction (XRD) analysis revealed a decrease in the crystallization degree with increasing Co content. The X-ray absorption near-edge structure (XANES) and X-ray photoelectron spectroscopies (XPS) revealed that the Co2+ ions preferentially occupied the Zn2+ sites and that the oxygen vacancy concentration increased as the amount of cobalt increased. Electrical measurements showed that the Co dopants not only enhanced the sensor response at low ozone levels (ca. 42 ppb) but also led to a decrease in the operating temperature and improved selectivity. The enhancement in the gas-sensing properties was attributed to the presence of oxygen vacancies, which facilitated ozone adsorption. (AU)

• FAPESP's process: 12/15170-6 - Synthesis and characterization of ZnO thin and thick films : application as gas sensors
• Grantee: Ariadne Cristina Catto
• Support Opportunities: Scholarships in Brazil - Doctorate
• FAPESP's process: 13/07296-2 - CDMF - Center for the Development of Functional Materials
• Grantee: Elson Longo da Silva
• Support Opportunities: Research Grants - Research, Innovation and Dissemination Centers - RIDC
• FAPESP's process: 13/09573-3 - Synthesis and Characterization of the ZnO/SnO2 Heterostructures obtained by Hydrothermal Method: Gas Sensor Applications
• Grantee: Luís Fernando da Silva
• Support Opportunities: Scholarships in Brazil - Post-Doctoral