Growth and characterization of (Zn,Sn,Ga)As2 thin films grown on GaAs(001) substrate by molecular beam epitaxy
文摘
Ga-incorporated ZnSnAs2 thin films were grown on semi-insulating GaAs(001) substrate by molecular beam epitaxy, and the structural, compositional, and electrical properties were characterized with respect to achieving conduction-type control. Compositional analysis with an electron-probe micro analyzer indicated that Ga atoms are substituted for cation (Zn and Sn) atoms and that the Ga/Sn beam equivalent pressure ratio has only a small influence on the Ga concentration. In addition, the composition ratios of Zn to all the cation sites were 2.0–5.7% smaller than that of Sn. 2θ/θ-scan X-ray diffraction analyses confirmed the epitaxial growth of (Zn,Sn,Ga)As2 thin films on GaAs(001) substrates. Reciprocal space maps revealed that these thin films are almost fully relaxed, and the lattice constants are in good agreement with Vegard's law. Hall effect measurements of all the (Zn,Sn,Ga)As2 thin films indicated n-type conductivity, which was due to the high Ga content of 44.1–47.8% on the cation sites.