The electrical properties of vacuum deposited tellurium films

A study has been made of the electrical properties of tellurium films deposited onto two different substrate materials, 7059 alkali free glass and single crystal potassium bromide. The films were always p-type with crystallographic defects resulting in the formation of additional acceptor centres. The carrier mobility was found to be dependent on temperature through an equation of the form $\text{μ}{}_{\mathrm{<mtext>H</mtext>}}\text{= μ}{}_0\text{exp}\text{(}\text{?E}\text{kT)}$, which is typical of polycrystalline films, where the effects of grain boundaries predominate. The value of μ₀ was found to vary linearly with crystallite size for specimens with a comparable carrier concentration. Crystalline defects, within the grains, were also found to be significant in determining the value of the carrier mobility. At no time was there any evidence to suggest that surface scattering was significant in tellurium films.