Isothermal capacitance transient spectroscopy study on trap levels in polycrystalline SnO₂ ceramics

Abstract

The unusual sigmoidal behavior between electrical resistivity and inverse temperature in polycrystalline porous SnO2 was intensively investigated by detecting the localized traps formed at the interparticle through the measurement of Isothermal Capacitance Transient Spectroscopy. A trap of 1.0 eV was evaluated at a higher temperature range of 460–500 °C, and 0.6 eV trap at a lower temperature range 200–280 °C. It seems that the trap of 1.0 eV originates from O2− and 0.6 eV from O− defect center. Time constants which were determined at the peak position of ICTS spectra, S(t), were increased with the increase of temperature at the intermediate temperature range, indicative of the competition among various kinds of traps. The active competition among various traps is one of the causes that result in prominent gas sensitivity in polycrystalline porous SnO2.

Investigation of the electrical properties of SnO2 varistor system using impedance spectroscopy

“…These results indicate that there are at least two kinds of defects or adsorbed species at the grain boundary region with different activation energies. Kim et al 16 observed that the activation energies for the OЈ and OЉ species on the SnO 2 surface are 0.6 and 1.0 eV, respectively. These energies are almost equal to those observed in the present article ͑0.7 and 1.0 eV͒ for the SCNCr compounds at temperatures higher than 200°C, as can be seen in Tables III and IV.…”

Direct Electron Transfer to Cytochrome c Induced by a Conducting Polymer

“…Among redox proteins, cytochrome c (cyt c) is probably one of the most extensively explored compound due to its key role in the respiratory chain [7][8][9][10][11][12][13] . Cyt c is a water soluble heme protein, with spherical shape and near 3 nm in diameter, which has the function of accepting electrons from cyt c reductase and delivering them to cyt c oxidase in the mitochondrial inner-membrane 14 .…”

Effect of Zn2SnO4 on the sintering and electrical properties of SnO2 ceramics

“…Bueno et al has reported that oxygen plays key role at grain boundary and the negative charged oxygen is necessary for the barrier formation [4,15]. On SnO 2 grain boundary, the activation energy E a about 0.6 eV and 1.0 eV for O − and O 2− , respectively was calculated by Kim et al [16]. Bueno at al.…”