Theory of temperature coefficient of resistivity: Application to amorphous Si and Ge
Department of Physics and Astronomy, Ohio University - Athens, OH 45701, USA
Accepted: 1 March 2012
By invoking the microscopic response method in conjunction with a reasonable set of approximations, we obtain new explicit expressions for the electrical conductivity and temperature coefficient of resistivity (TCR) in amorphous semiconductors, especially a-Si:H and a-Ge:H. The predicted TCR for n-doped a-Si:H and a-Ge:H is in agreement with experiments. The conductivity from the transitions from a localized state to an extended state (LE) is comparable to that from the transitions between two localized states (LL). This resolves a long-standing anomaly, a “kink" in the experimental log10σ-vs.-T−1 curve.
PACS: 71.23.An – Theories and models; localized states / 72.20.Dp – General theory, scattering mechanisms / 71.38.Ht – Self-trapped or small polarons
© EPLA, 2012