nl202782q_si_001.pdf (1.41 MB)
Crystal Face-Dependent Nanopiezotronics of an Obliquely Aligned InN Nanorod Array
journal contribution
posted on 2012-02-08, 00:00 authored by Nai-Jen Ku, Jun-Han Huang, Chao-Hung Wang, Hsin-Chiao Fang, Chuan-Pu LiuThis paper proposes an obliquely aligned InN nanorod
array to maximize
nanorod deformation in the application of nanopiezotronics. The surface-dependent
piezotronic I–V characteristics
of the InN nanorod array with exposed polar (0002) and semipolar (1̅102)
planes were studied by conductive atomic force microscopy. The effects
of the piezopotential, created in the InN under straining, and the
surface quantum states on the transport behavior of charge carriers
in different crystal planes of the InN nanorod were investigated.
The crystal plane-dependent electron density in the electron surface
accumulation layer and the strain-dependent piezopotential
distribution modulate the interfacial contact of the Schottky characteristics
for the (0002) plane and the quasi-ohmic behavior for the (1̅102)
plane. Regarding the piezotronic properties under applied forces,
the Schottky barrier height increases in conjunction with the deflection
force with high current density at large biases because of tunneling.
The strain-induced piezopotential can thus tune the transport process
of the charge carriers inside the InN nanorod over a larger range
than in ZnO. The quantized surface electron accumulation layer is
demonstrated to modulate the piezopotential-dependent carrier transport
at the metal/InN interfaces and become an important factor in the
design of InN-based piezotronic devices and nanogenerators.