High-magnetic-field studies of transport properties in Sn-doped InSb thin films on GaAs(100) substrates

Magnetotransport measurements for Sn-doped InSb thin films with thickness of d = 0.3 - 1.0 mum grown on semi-insulating GaAs(l 0 0) substrates by MBE have been performed under high-magnetic fields up to 53 T using a pulsed magnet at 4.2 K. The Shubnikov-de Haas (S-dH) oscillations including 0(+) maximum corresponding to the lowest Landau level (i = 0) as well as the spin-splittings (for i = 1 and 2) have been observed for d > 0.5 mum on the positive magnetoresistance (MR) (p(xx)) in perpendicular magnetic fields. The plateau-like structure of the Hall resistance (p(xy)) around the last minimum of p(xx) and the slope of its sublinear dependence on magnetic field becomes clear as decreasing d. The positive MR of p(xx) and the sublinear behavior of p(xy) have been consistently explained for d = 1.0 mum by the two-layer model assuming the presence of the accumulation later with low mobility at the InSb/GaAs interface which act as the parallel conduction channel with the high-mobility layer in the InSb film. Moreover, the shoulder corresponding to the zeroth maximum which has remained ambiguous about the appearance in p(zz) for bulk systems has been apparently observed for all measured films. (C) 2004 Elsevier B.V. All rights reserved.