Direct imaging of atomic scale structure and electronic properties of GaAs wurtzite and zinc blende nanowire surfaces.
Using scanning tunneling microscopy and spectroscopy we study the atomic scale geometry and electronic structure of GaAs nanowires exhibiting controlled axial stacking of wurtzite (Wz) and zinc blende (Zb) crystal segments. We find that the nonpolar low-index surfaces {110}, {101[overline]0}, and {112[overline]0} are unreconstructed, unpinned, and without states in the band gap region. Direct comparison between Wz and Zb GaAs reveal a type-II band alignment and a Wz GaAs band gap of 1.52 eV.
Department of Physics, Lund University , P.O. Box 118, 22 100 Lund, Sweden.
M
M
Hjort
S
S
Lehmann
J
J
Knutsson
R
R
Timm
D
D
Jacobsson
E
E
Lundgren
K A
KA
Dick
A
A
Mikkelsen