The change of electrical conduction in the valence/conduction band to the impurity band in CdSe<inf>x</inf>Te<inf>1-x</inf> thin films

Reported here are the results of investigations carried out on the mechanism of electrical conduction in CdSexTe1-x thin films between 300 and 125 K in vacuum. All the films showed a transition from grain boundary limited conduction in the conduction/valence band to phonon assisted hopping via the impurity band (impurity band conduction) at around 280-290 K. The grain boundary limited conduction showed an activation energy equal to about 0.14 eV and conduction via impurity band showed an activation energy of about 0.02 eV, which is characteristic of phonon assisted hopping conduction.