Low-frequency noise characterization of ZnO nanorod back-gate field-effect transistor structure

We report the results of low-frequency noise characterizations of back-gate n-channel ZnO nanorod field-effect transistor (FET) structure at room temperature. The noise in source-drain current was measured at zero gate bias and different source-drain biases. The power spectral density of noise current showed, in general, 1/f behavior with some variations. The power index of current dependence of the noise density at 10 Hz was about 1.5. The Hooge parameter obtained from the noise density at 10 Hz was comparable to or smaller than carbon nanotube transistors and much higher than those of silicon nanowires and conventional silicon transistors, indicating that special attention should be addressed to low-frequency noise in device applications. Possible noise sources are discussed with different models.