Temperature dependent resistivity study on zinc oxide and the role of defects

• Published in: Materials science in semiconductor processing 2013-04, Vol.16 (2), p.332-336
• Main Authors: Roy, Tapatee Kundu, Sanyal, D., Bhowmick, Debasis, Chakrabarti, Alok
• Format: Article
• Language: English
• Subjects: Annealing; Applied sciences; Cold working, work hardening; annealing, quenching, tempering, recovery, and recrystallization; textures; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Cross-disciplinary physics: materials science; rheology; Defect annealing; Defects; Electrical properties; Electrical resistivity; Electronic structure and electrical properties of surfaces, interfaces, thin films and low-dimensional structures; Electronic transport in multilayers, nanoscale materials and structures; Exact sciences and technology; Heat treatment; Materials science; Mathematical analysis; Metals. Metallurgy; Optical properties and condensed-matter spectroscopy and other interactions of matter with particles and radiation; Origins; Other interactions of matter with particles and radiation; Physics; Positron annihilation; Positron annihilation spectroscopy; Production techniques; Semiconductor; Semiconductors; Treatment of materials and its effects on microstructure and properties; Zinc oxide
• ISSN: 1369-8001; 1873-4081
• DOI: 10.1016/j.mssp.2012.09.018

The temperature dependent (30–550°C) resistivity of zinc oxide (ZnO) has been studied by the standard four probe resistivity method. The room-temperature resistivity of the sample is measured as 0.75MΩm. Resistivity versus temperature plot of the sample shows normal NTCR (negative temperature coefficient of resistance) behavior up to 300°C. However, a crossover from NTCR to a PTCR (positive temperature coefficient of resistance) behavior is observed at ∼300°C. The origin of the PTCR behavior is explained with the defects present in the ZnO annealed up to 550°C. Temperature dependent S-parameter (positron annihilation line-shape parameter) indicates the formation of oxygen vacancy like defects in this temperature region. At the PTCR region, the activation energy for the electron conduction is calculated ∼2.6eV. This value is very close to the theoretically predicted defect level energy of 2.0eV for oxygen vacancies present in ZnO.