NIST logo

Publication Citation: Low-frequency noise in gallium nitride nanowire mechanical resonators

NIST Authors in Bold

Author(s): Jason Gray; Kristine A. Bertness; Norman A. Sanford; Charles T. Rogers;
Title: Low-frequency noise in gallium nitride nanowire mechanical resonators
Published: December 07, 2012
Abstract: We report on the low-frequency 1/f (flicker) parameter noise displayed by the resonance frequency and resistance of doubly clamped c-axis gallium nitride nanowire (NW) mechanical resonators. The resonators are electrostatically driven and their mechanical response is electronically detected via NW piezoresistance. With an applied dc voltage bias, a NW driven near its mechanical resonance generates a Lorentzian current signal which, when lock-in detected, displays a modulated, drive-frequency-dependent 1/f noise component. This noise is proportional to the square of the derivative of the Lorentzian lineshape with a magnitude highly dependent on NW dc bias voltage conditions, consistent with noise in the NW's resistance leading to temperature, and hence resonance frequency noise due to local Joule heating. An example device with a 27.8 MHz resonance frequency and 220 k{Ω} resistance experiences an approximate resonance frequency shift of -5.8 Hz/nW. In terms of NW resistance change, this corresponds with shifts of 0.1 Hz/{Ω} and 2.6 Hz/{Ω} at 1 V bias and 4 V bias, respectively, with an average resistance fluctuation of 1 k{Ω} in a 1-second bandwidth.
Citation: Applied Physics Letters
Volume: 101
Pages: pp. 233115-1 - 233115-5
Keywords: gallium nitride nanowires; nanomechanical resonators; 1/f noise
Research Areas: Nanowires, Optoelectronics
PDF version: PDF Document Click here to retrieve PDF version of paper (875KB)