Effect of doping on transport properties of InSb epilayers grown by MOCVD and MBE

Temperature-dependent carrier transport properties of two InSb epilayers grown on GaAs substrates by Molecular Beam Epitaxy (MBE) and Metal Organic Chemical Vapor Deposition (MOCVD) are investigated. The InSb epilayer grown by MBE was undoped, but the undoped InSb epilayer grown by MOCVD was grown on a thin Zndoped InSb layer. Hall Effect results showed that the Hall coefficients (RH) for InSb grown by MBE and MOCVD are negative in temperature ranges 4.2 K-300 K and 200 K-300 K, respectively. However, for the InSb sample grown by MOCVD, RH switches from a positive to a negative value for temperatures above similar to 180 K, which could be due to the capture electrons generated from dislocation between InSb and GaAs by Zn atoms. The electron mobilities of InSb grown by MBE and MOCVD were 38,247 and 51,704 cm(2)/Vs, respectively. Low-temperature magnetoresistance measurements showed clear Shubnikov-de-Haas oscillations (SdH) in MBE InSb; however, no SdH oscillations were observed in MOCVD InSb samples.