摘要
Using low-frequency noise spectroscopy to explore the physical origins of electrical fluctuations in ZnO nanowire (NW) phototransistors featuring a metal-NW-metal configuration, we have found that bulk mobility scatterings gave rise to electrical fluctuations in the low-gate voltage (V G ) regime, providing values of Hooge's constant in the ranges 6.0-9.6×10 -3 and in the dark and under UV excitation, respectively. When moving into the higher V G regime, we assign the electrical fluctuations to an interaction process involving trapping and detrapping of channel carriers by charge traps located near the NW-dielectric interface, suggesting that the mechanism of the electrical fluctuation transitioned from bulk NW-dominated to NW/dielectric interface-dominated regimes. We have also addressed the effective density of interface traps responsible for the electrical fluctuations in the high-V G region. This report provides physical insight into the origins of electrical fluctuations in NW phototransistors. © 2014 IOP Publishing Ltd.