Suppression of twin formation in layered In2Se3 grown on GaAs(111)

We propose novel buffer layers consisting of the layered defect zincblende (In_xGa_1-x)₂Se₃ compounds for the GaAs on Si(111) system. The layered structured materials are suitable for lattice mismatch and thermal expansion mismatch buffer layers. However, weak van der Waals bonding may cause twin crystal domain formation during the crystal growth. We investigated In₂Se₃ growth on GaAs(111) just and vicinal substrates by MBE and compared twin crystal formation, surface morphology and crystal quality. The vicinal substrates suppress twin formation by predominating the step-flow growth at the surface step edge. To eliminate twin crystal domains and to improve crystal quality, the optimization of the surface step structure is necessary.