Size effect of carrier heating in bismuth films

The size effect in the heating of the electron gas in bismuth films is considered. It is shown that in the range of thicknesses in which the classical size effect appears in the film conductivity the heating size effect does not vanish even in the absence of inelastic surface scattering mechanisms. We experimentally studied the thickness dependence of the nonohmic coefficient of bismuth films with a thickness of 1200−3400 Å at T = 300 and 78 °K. The calculated and experimental results are in satisfactory agreement when the relative rate of electron energy loss at the surface is ξ = 3·104 at T = 300 °K and 4·10−3 at 78 °K.