ELECTRIC AND DIELECTRIC-PROPERTIES OF SOLUTION GAS INTERFACE-GROWN PBS FILMS

Dielectric properties and I-V characteristics of solution-gas interface-formed PbS thin-film capacitors (Al/PbS/Al) of various thicknesses have been studied in the frequency range 10-10(6) Hz at various temperatures (300-443 K). Current-voltage (I-V) characteristics show space-charge-limited conduction. Dielectric constant (epsilon) increases with increasing film thickness and temperature and decreases with increase of frequency. The loss factor (tan delta) peaks observed in tan delta vs frequency and tan delta vs temperature reveal relaxation effect from dipolar orientation. These maxima shift to higher-temperature region with increasing frequency. The large increase in capacitance (C) and dielectric constant (epsilon) towards low-frequency (f) region indicates the possibility of an interfacial polarization mechanism in this region.