Crystal face-dependent nanopiezotronics of an obliquely aligned InN nanorod array.
This 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 ( ̅1102) 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 ( ̅1102) 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.
Department of Materials Science and Engineering, National Cheng Kung University, Tainan 701, Taiwan.
Nai-Jen
NJ
Ku
Jun-Han
JH
Huang
Chao-Hung
CH
Wang
Hsin-Chiao
HC
Fang
Chuan-Pu
CP
Liu
D003460:Crystallization; D004579:Electron Transport; D007204:Indium / Q000737:chemistry*; D036103:Nanotechnology / Q000295:instrumentation*; D043942:Nanotubes / Q000737:chemistry*; D010316:Particle Size; D013499:Surface Properties
D007204:Indium; C513701:indium nitride