Original scientific paper
Transport properties of PbTe9.7Sb0.3 thin films
Zeinab S. El-Mandouh
; Physics Department, National Research Center, Cairo, Egypt
Mohamed El-Shabasy
; Physics Department, National Research Center, Cairo, Egypt
Abstract
Thin films of (PbTe)9.7Sb0.3 per weight of different thicknesses have been prepared on quartz substrate by vacuum thermal evaporation. Heating-cooling cycles indicate an increase of resistivity with successive cooling cycles. These observations can be explained by considering the desorption of absorbed gas molecules and creation of defects during the heating process. Isothermal annealing effect was studied. Plots of logarithm of resistivity versus temperature were analyzed to derive the activation energy for the defect formation. The apparent value of the energy was 0.18 eV, i.e. about a half of the activation energy for conduction. The activation energy for conduction and resistivity are thickness dependent. The optical spectrum of (PbTe)9.7Sb0.3 in the infrared region was measured. From the spectrum, we derived the values of the direct and indirect energy gaps of 0.29 and 0.19 eV, respectively.
Keywords
Hrčak ID:
299438
URI
Publication date:
1.3.1995.
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