High field conduction in Pb doped amorphous Se-Te system

In the present study, DC conductivity measurements of as-Se80-xTe20Pbx (x = 0, 1 and 2) glassy alloys are made in the temperature range 298-318 K and in the voltage range 0-180 V. Current-voltage (I-V) characteristics point toward ohmic behavior at low electric field and non-ohmic is observed at high electric field. The variation of ln(I/V) against V are nearly found straight curves but slope of these curves does not decrease linearly with temperature indicates that the space charge limited conduction (SCLC) is absent. Instead the linear relation between ln(I) and V-1/2 confirms that the conduction is either Poole-Frenkel type or Schottky emission. A detailed analysis shows that the dominant mechanism is Poole-Frenkel type conduction.