Electrical properties of flash evaporated thin films of InTe

Thin films of InTe formed by flash evaporation technique onto goldseal glass, freshly cleaved mica, and sodium chloride substrates, kept at room temperature (approximately 303 K) in a vacuum of approximately 2.7 x 10-4 Pa, are found to be amorphous. These films are subjected to post deposition heat treatment, carried out through different annealing cycles, monitoring resistance simultaneously. The room temperature electrical resistivity is observed to increase in the initial heating cycles indicating annealing of defects and homogenizing of the film structure. In the latter annealing cycles, crystallinity is setting in as revealed from the decrease in the room temperature electrical resistivity. Epitaxial growth is observed in thicker films after annealing. A decrease in resistivity of the order of 105 is observed when the degree of crystallinity significantly increases. The structure of the films is determined by electron diffraction before and after this sudden change in electrical resistivity to correlate the observed change with the structure. Films are also formed onto the substrates kept at higher temperatures to see the effect of substrate temperature on the structure and electrical properties. Hall mobility and thermoelectric power measurements are made on the crystalline indium telluride films. (author)