Electrical properties of Pb x Sn 1‐x S thin films prepared by hot wall deposition method

The Pb x Sn 1‐x S (x = 0 – 0.25) thin films were prepared on glass substrates by hot wall vacuum deposition. The films were polycrystalline monophase in nature and had orthorhombic crystal structure. The thickness of the films was about 2‐3 μm. The temperature dependences of the conductivity were measured in the temperature range from 150 to 420 K. The films revealed p‐type of conductivity. The Seebeck coefficient and conductivity values of the films was in the range of α = 6 – 360 μV/K and σ = 4.8×10 ‐5 – 1.5×10 ‐2 Ω ‐1 ·cm ‐1 , respectively, at room temperature depending on concentration of the lead in the films. The lead atoms created the substitution defects Pb Sn in the crystal lattice of the Pb x Sn 1‐x S. These defects formed the donor energy levels in the band gap. The activation energy of the films increased in the range ΔE a = 0.121 – 0.283 eV with increasing of the lead concentration. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)