Axial strain in GaAs/InAs core-shell nanowires

We study the axial strain relaxation in GaAs/InAs core-shell nanowire heterostructures grown by molecular beam epitaxy. Besides a gradual strain relaxation of the shell material, we find a significant strain in the GaAs core, increasing with shell thickness. This strain is explained by a saturation of the dislocation density at the core-shell interface. Independent measurements of core and shell lattice parameters by x-ray diffraction reveal a relaxation of 93% in a 35 nm thick InAs shell surrounding cores of 80 nm diameter. The compressive strain of −0.5% compared to bulk InAs is accompanied by a tensile strain up to 0.9% in the GaAs core.

[1]  Ullrich Pietsch,et al.  High-Resolution X-Ray Scattering , 2004 .

[2]  Hiroshi Yamaguchi,et al.  Atomic-scale imaging of strain relaxation via misfit dislocations in highly mismatched semiconductor heteroepitaxy: InAs/GaAs(111)A , 1997 .

[3]  U. Pietsch,et al.  Structural evolution of self‐assisted GaAs nanowires grown on Si(111) , 2011 .

[4]  L. Samuelson,et al.  Structural investigations of core-shell nanowires using grazing incidence X-ray diffraction. , 2009, Nano letters.

[5]  Y. Mai,et al.  Super Deformability and Young’s Modulus of GaAs Nanowires , 2011, Advanced materials.

[6]  Sourobh Raychaudhuri,et al.  Critical dimensions in coherently strained coaxial nanowire heterostructures , 2006 .

[7]  T. Schäpers,et al.  Realization of nanoscaled tubular conductors by means of GaAs/InAs core/shell nanowires , 2013, Nanotechnology.

[8]  T. Guhr,et al.  Strain in semiconductor core-shell nanowires , 2009, 1006.0391.

[9]  H. Shtrikman,et al.  InAs/GaAs Core–Shell Nanowires , 2011 .

[10]  K. Kavanagh,et al.  Transport and strain relaxation in wurtzite InAs–GaAs core-shell heterowires , 2011 .

[11]  K. Kavanagh,et al.  Faster radial strain relaxation in InAs-GaAs core-shell heterowires , 2012 .

[12]  Martin Heiss,et al.  Impact of surfaces on the optical properties of GaAs nanowires , 2010 .

[13]  Measurement of Young’s modulus of GaAs nanowires growing obliquely on a substrate , 2012 .

[14]  F. Bechstedt,et al.  Polytypism of GaAs, InP, InAs, and InSb: An ab initio study , 2011 .

[15]  H. Schulte-Schrepping,et al.  The high-resolution diffraction beamline P08 at PETRA III. , 2012, Journal of synchrotron radiation.

[16]  U. Pietsch,et al.  Structural polytypism and residual strain in GaAs nanowires grown on Si(111) probed by single‐nanowire X‐ray diffraction , 2012 .

[17]  P. McIntyre,et al.  Synthesis and strain relaxation of Ge-core/Si-shell nanowire arrays. , 2008, Nano letters.

[18]  Xiaocheng Jiang,et al.  InAs/InP radial nanowire heterostructures as high electron mobility devices. , 2007, Nano letters.

[19]  D. Grützmacher,et al.  Ga-assisted MBE growth of GaAs nanowires using thin HSQ layer , 2012 .

[20]  T. Schäpers,et al.  Molecular beam epitaxy growth of GaAs/InAs core-shell nanowires and fabrication of InAs nanotubes. , 2012, Nano letters.

[21]  Y. S. Zhang,et al.  Size dependence of Young's modulus in ZnO nanowires. , 2006, Physical review letters.