Dielectric constant and dissipation factor of lead phthalocyanine have been experimentally studied here as functions of frequency and temperature. Dielectric constant increases by one order of magnitude with temperature showing pyroelectric behaviour. It is explained that molecular distortion leads to increased dielectric constant.

Metal-semiconductor contacts are drawing increasing attention due to their potential for applications in devices and integrated circuits. Experimentally, lower barrier heights have been reported more often for metallic contacts onp-type semiconductors. Here we report our results regarding barrier height of zinc onp-type germanium. The result is discussed in light of the mechanisms which could reduce the pinning effect in such contacts which are normally thought to be responsible for the observation of low barrier heights onp-type semiconductors.

The tin selenide crystals with different proportions of Sn and Se were grown by a direct vapour-transport technique. The layer by layer growth of crystals from the vapour phase was promoted by screw dislocation mechanism. The powder X-ray diffraction (XRD) shows good crystallinity of grown compound. The XRD patterns of grown compounds are well-indexed to orthorhombic structure. In the off-stoichiometric compound, evidence of SnSe$_2$ secondary phase is observed due to excess of selenium. The morphological investigations were carried out using a Carl Zeiss optical microscope. The electron diffraction was also recorded from tiny flakes using a transmission electron microscope. The electrical resistivity both parallel and perpendicular to the c-axis was measured in the temperature range of 303–490 K and activation energy was also calculated using Arrhenius relation. The electrical study depicts the extrinsic semiconducting nature of grown compositions.