Oscillations in the thickness dependences of the room-temperature Seebeck coefficient in SnTe thin films

The dependences of the Seebeck coefficient S on the thickness ( d = 5–110 nm) of SnTe thin films grown by thermal evaporation in vacuum on (001)KCl substrates were obtained at room temperature. Distinct oscillations in the S( d)-dependences were observed and attributed to the size quantization effect in SnTe thin films. The monotonic component of the d-dependences of S decreases with increasing thickness. In this connection it is suggested that the equilibrium concentration of non-stoichiometric cation vacancies depends on the SnTe film thickness.