The electrical conductivity in doped semiconductors in the strongly localized variable range hopping regime is currently explained as phonon-assisted electron hopping. While investigating the non-Ohmic behavior of doped silicon at temperatures of 0.05-1 K, we found strong evidence for the existence of separate temperatures for the electron and phonon systems analogous to the hot-electron effect in metals. This behavior cannot easily be explained by phonon-assisted hopping and seems to favor instead a direct electron-electron interaction at low temperature. A hot-electron model makes definite predictions for the dependence of the electrical conductivity on the bias power, the frequency dependence of the resistance nonlinearities, and for an additional noise term. We have made a systematic investigation of these quantities, and find all of them in good agreement with the model predictions over a wide range of parameters.
|Original language||English (US)|
|Journal||Physical Review B - Condensed Matter and Materials Physics|
|State||Published - Oct 18 2007|
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics