ONE-DIMENSIONAL SEMICONDUCTING AND PIEZOELECTRIC NANOSTRUCTURES - SYNTHESIS, GROWTH MECHANISMS AND PROPERTIES

Zhong Lin Wang

School of Materials Science and Engineering, Georgia Institute of Technology,  Atlanta 30332-0245

Nanowire and nanotube based materials have been demonstrated as building blocks for anocircuits, nanosystems and nano-optoelectronics. Quasi-one-dimensional nanostructures (so called nanobelts or nanoribbons) have been successfully synthesized for semiconducting oxides of zinc, tin, indium, cadmium and gallium, by simply evaporating the desired commercial metal oxide powders at high temperatures [1]. The belt-like morphology appears to be a unique and common structural characteristic for the family of semiconducting oxides with cations of different valence states and materials of distinct crystallographic structures. Using the technique demonstrated for measuring the mechanical properties of carbon nanotubes based on in-situ transmission electron microscopy [2,3], the bending modulus of the oxide nanobelts, the workfunction at the tip have been measured. Field effect transistors [4] and ultra-sensitive nano-size gas sensors [5], nanoresonators and nanocantilevers [6] have also been fabricated based on individual nanobelts. Thermal conductivity of a nanobelt has also been measured. Very recently, nanobelts, nanorings and nanosprings that exhibit piezoelectric properties have been synthesized, which are potential candidates for nano-scale traducers, actuators and sensors [7, 8, 9, 10]. This presentation will focus on our recent progress in the controlled growth, nano-scale property measurements and nano-size device fabrication using oxide nanostructures that are semiconducting and piezoelectric.

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[2] P. Poncharal, Z.L. Wang, D. Ugarte and W.A. de Heer, Science, 283 (1999) 1513; Electron Microscopy of Nanotubes, ed. Z.L. Wang and C. Hui, Kluwer Academic Publisher (2003).

[3] R.P. Gao, Z.L. Wang, Z.G. Bai, W. de Heer, L. Dai and M. Gao, Phys. Rev. Letts., 85 (2000) 622; Z.L. Wang, P. Poncharal and W.A. De Heer, Pure Appl. Chem. Vol. 72 (2000) 209.

[4] M. Arnold, P. Avouris, Z.L. Wang,. Phys. Chem. B, 107 (2002) 659.

[5] E. Comini, G. Faglia, G. Sberveglieri, Zhengwei Pan, Z. L. Wang Appl. Phys. Letts., 81 (2002) 1869.

[6] W. Hughes and Z.L. Wang, Appl. Phys. Letts., 82 (2003) 2886.

[7] X.Y. Kong and Z.L. Wang, Nano Letters, 2 (2003) 1625 + cover.

[8] Z.L. Wang, X.Y. Kong and J.M. Zuo, Phys. Rev. Letts. 91 (2003) 185502.

[9] " Nanowires and Nanobelts ? materials, properties and devices; Vol. I: Metal and Semiconductor Nanowires”, Vol. II: Nanowires and Nanobelts of Functional Materials” edited by Z.L. Wang, Kluwer Academic Publisher (2003).

[10] X.Y. Kong, Y. Ding, R.S. Yang, Z.L. Wang, Science, 303 (2004) 1348.

[11] For details: http://www.nanoscience.gatech.edu/zlwang/