Nearly Lattice Matched GaAs/Pb(1-x)Sn(x)Te Core-Shell Nanowires

TL;DR

This study explores the growth and structural properties of nearly lattice-matched GaAs/Pb(1-x)Sn(x)Te core-shell nanowires, highlighting their potential for topological crystalline insulator applications.

Contribution

It demonstrates the epitaxial growth of Pb(1-x)Sn(x)Te shells on GaAs nanowires with minimal lattice mismatch and characterizes their crystalline orientations and compositions.

Findings

Lattice mismatch along nanowire axis is less than 4%.

Pb(1-x)Sn(x)Te shells exhibit specific crystalline orientations.

Shell composition varies from SnTe to PbTe with changing Sn content.

Abstract

We investigate the full and half-shells of Pb(1-x)Sn(x)Te topological crystalline insulator deposited by molecular beam epitaxy on the sidewalls of wurtzite GaAs nanowires (NWs). Due to the distinct orientation of the IV-VI shell with respect to the III-V core the lattice mismatch along the nanowire axis is less than 4%. The Pb(1-x)Sn(x)Te solid solution is chosen due to the topological crystalline insulator properties for some critical concentrations of Sn (x >= 0.4). The IV-VI shells are grown with different compositions spanning from binary SnTe, through Pb(1-x)Sn(x)Te with decreasing x value down to binary PbTe (x = 0). The samples are analyzed by scanning transmission electron microscopy, which reveals the presence of (110) or (100) oriented binary PbTe and (100)Pb(1-x)Sn(x)Te on the sidewalls of wurtzite GaAs NWs.