The Band-Structure Parameters of Bi1 –xSbx (0 ≤ x ≤ 0.15) Thin Films on Substrates with Different Thermal-Expansion Coefficients

Resumo

The results of calculation of the charge-carrier concentration in bismuth–antimony films on substrates with different coefficients of thermal expansion are reported. The antimony content in the films is in the range 0–15 at %. Calculation is performed on the basis of experimental studies of the galvanomagnetic properties of the films. It is shown that the concentration is considerably higher in the case of substrates with a large coefficient of thermal expansion. The results of calculation of the position of the valence and conduction bands at 77 K in relation to the coefficient of thermal expansion of the substrate are reported. It is shown that, as the thin films experience in-plane strains defined by a difference between the coefficients of thermal expansion of the film and substrate materials, the position of the valence and conduction bands in the films changes relative to the position of the bands in the single crystal with the corresponding composition.