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Novel Devices

Personnel: KunHo Yoon, In Soo Kim, Chang-Hua Liu
Collaborators: T. Marks, M. Hersam
Applications: ultra-sensitive force detection, novel logic devices

The extreme aspect ratio of nanowires leads to new properties and functions that can be exploited in novel devices. We are exploring the outstanding mechanical properties of single crystal silicon nanowires as ultra-sensitive force detectors with collaborators at the University of Illinois. We are also exploring the unique and fascinating properties of the oxide nanobeams that undergo an insulator to metal transition near room temperature. Organic dielectrics are being integrated with nanowire devices in collaboration with Tobin Marks.

Ultrasensitive Force Detection

Silicon nanowires are single crystals with potentially ideal mechanical properties, but they are not useful without a means to stimulate and detect nanowire motion. Through a collaboration with Raffi Budakian’s group, we have established Michelson interferometry as a viable approach to detect motion in free-standing Si nanowires. The nanowires exhibit ultra-low mechanical dissipation and excellent displacement sensitivity.

J. M. Nichol, E. R. Hemesath, L. J. Lauhon, and R. Budakian, "Displacement detection of silicon nanowires by polarization-enhanced fiber-optic interferometry," Applied Physics Letters 93, 193110 (2008).

Phase-change Materials

Vanadium oxide undergoes an insulator-to-metal transition near room temperature, leading to applications in thermochromic windows, gas sensors, and novel logic devices. We have provided new insights into the electrical switching behavior of vanadium oxide nanobeams by directly correlating the electrical properties with the spatial domain structure in real time. We confirmed the possibility of directly inducing the insulator-metal transition in the absence of a structural phase transformation, supporting the proposal to engineer a Mott field effect transistor from this material.

S. X. Zhang, J. Y. Chou, & L. J. Lauhon, “Direct correlation of structural domain formation with the metal insulator transition in a VO2 nanobeam,” Nano Letters 9, (12) 4527-4532 (2009).

Additional References