Abnormal conductivity behavior in porous lead telluride films

We report the experimental observation of the novel phenomenon of the resistivity decrease in porous PbTe layers during the pore formation process. Investigations were performed on the n-PbTe films with 2.3-μm thickness, which were near the point of the conductivity-type inversion at room temperature. Anodic electrochemical treatment for the porous layers with 41% to 52% porosity fabrication was performed using a KOH-based Norr electrolyte solution. For the porous lead telluride layers, the resistivity value at 300 K decreased 2.5 to 3 times. For the explanation of the observed phenomenon, a physical model is proposed which takes into account the Pb/Te ratio change during the anodic treatment.