title: Low-frequency (1/f) noise in nanocrystal field-effect transistors.
abstract: We investigate the origins and magnitude of low-frequency noise in high-mobility nanocrystal field-effect transistors and show the noise is of 1/f-type. Sub-band gap states, in particular, those introduced by nanocrystal surfaces, have a significant influence on the 1/f noise. By engineering the device geometry and passivating nanocrystal surfaces, we show that in the linear and saturation regimes the 1/f noise obeys Hooge's model of mobility fluctuations, consistent with transport of a high density of accumulated carriers in extended electronic states of the NC thin films. In the subthreshold regime, the Fermi energy moves deeper into the mobility gap and sub-band gap trap states give rise to a transition to noise dominated by carrier number fluctuations as described in McWhorter's model. CdSe nanocrystal field-effect transistors have a Hooge parameter of 3 × 10(-2), comparable to other solution-deposited, thin-film devices, promising high-performance, low-cost, low-noise integrated circuitry.
authors.affiliation: Department of Electrical and Systems Engineering, ‡Department of Materials Science and Engineering, and §Department of Chemistry, University of Pennsylvania , Philadelphia, Pennsylvania 19104, United States.
authors.forename: Yuming
authors.initials: Y
authors.lastname: Lai
authors.forename: Haipeng
authors.initials: H
authors.lastname: Li
authors.forename: David K
authors.initials: DK
authors.lastname: Kim
authors.forename: Benjamin T
authors.initials: BT
authors.lastname: Diroll
authors.forename: Christopher B
authors.initials: CB
authors.lastname: Murray
authors.forename: Cherie R
authors.initials: CR
authors.lastname: Kagan
keywords: 1/f noise; CdSe; charge transport; field-effect transistors; low-frequency noise; nanocrystals; trap states