Handbook of thin film technology

Study of scattering of charge carriers in thin films of (Bi0.25Sb0.75)2Te3 alloy with 2% excess Te

Study of the crystallization of antimony thin films by transmission electron microscopy observations and electrical measurements

Structure and properties of thin films.

Antimony thin films were vacuum deposited on glass substrates at room temperature. X-ray structural studies were performed. The thickness dependence of both the de electrical resistivity and the Hall coefficient were earried out at room temperature over a thickness range from 29 nm to 216 nm. The type of conduction, the concentration and the mobility of charge carriers were revealed. Analysis incorporating the electrical resistivity and the Hall effect data has led to the determination of the specular and non-specular size-effect parameters. Parameters such as the bulk resistivity (ϱ
0), bulk mean free path (λ
0), grain-boundary transmission coefficient (t), external surface parameters (U), surface scattering factor (p) and grain-boundary parameter (V), were all evaluated without using any adjusting parameters. Beside the background contribution to the film resistivity, an estimation of the contribution of the surface and grain-boundary to the film resistivity was also carried out.

Antimony thin-film transport properties and size effect

Thin antimony films of thicknesses in the range 30 to 200 nm have been vacuum deposited on glass substrates at room temperature. After annealing for about an hour at 500 K, the thermoelectric power and electrical resistivity were measured in vacuum as a function of temperature. The thermoelectric power and electrical conductivity data were combined and simultaneously analysed using the effective mean free path theory of size effect in thin films developed by Tellier and Pichard et al. In addition, their temperature dependence was also analysed. It was found that the thermoelectric power is positive and increases with increasing temperature and is inversely proportional to the thickness of the film. The electrical resistivity was found to be temperature dependent with the temperature coefficient of resistivity being positive, and inversely proportional to the thickness of the film. Analysis combining the data from the thermoelectric power and electrical conductivity measurements has led to the determination of mean free path, carrier concentration, effective mass, Fermi energy and the parameter \(U_g = (d ln l_g /d ln E)_{E = E_F } \) The data were analysed for least squares fitting by local functions, such as the spline functions, which eliminates possible errors in conventional least squares fitting of data using non-local functions valid throughout the range.

V. Damoddara Das

Papers

Size and temperature dependence of thermoelectric power and electrical resistivity of vacuum-deposited antimony thin films