Water assisted gate induced temporal surface charge distribution probed by electrostatic force microscopy

Abstract

Articles you may be interested inEffect of surface charge on water film nanoconfined between hydrophilic solid surfacesIn this paper, we present a quantitative method to measure charge density on dielectric layers using electrostatic force microscopy. As opposed to previous reports, our method, which is based on force curve measurements, does not require preliminary knowledge of the tip-sample capacitance and its derivatives. Using this approach, we have been able to quantify lateral and temporal SiO 2 surface charge distribution and have unveiled a gate-induced charge redistribution mechanism which takes place in the vicinity of grounded electrodes. We argue that this mechanism constitutes a dominant factor in the hysteresis phenomenon, which is frequently observed in the transfer characteristics of nano-scale devices. V C 2012 American Institute of Physics. [http://dx.

Water-assisted mobile charge induced screening and origin of hysteresis in carbon nanotube field-effect transistors

“…In a recent study, 27 we reported on gate-induced waterassisted surface charge redistribution on dielectric layers. Briefly, the temporal behavior for this phenomenon indeed follows an exponential time dependence which was attributed to charge transport along the oxide surface that acts as a leaky capacitor.…”

Imaging surface charge distribution near carbon nanotube device in aqueous environments

“…A similar charge distribution on the surface of silicon oxide under highly humid conditions (not in the solution environment) has been reported in electrical probing techniques and has been attributed to the formation of positive charges in the middle of the metallic electrodes. 30 Note that such an ion-induced PC (IPC) signal along the SWNT axis is pronounced when the ionic strength of the water is very low, e.g., less than $0:5 lM. The ionic strength tends to increase as the carbon dioxide (CO 2 ) from the ambient air dissolves into the solution.…”

Injection and Retention Characterization of Trapped Charges in Electret Films by Electrostatic Force Microscopy and Kelvin Probe Force Microscopy

“…[ 90 ] Other researchers also reported that atmospheric moisture and the water molecules in the film could increase the probability of charge injection and accelerate the diffusion of trapped charges. [ 2,46,47,60,78,87,101–105 ] In addition, a higher H 2 O and O 2 concentration may be one of the important factors in improving the charge trap rate. [ 66 ]…”

“…[ 16,40,42,44,46,47,55,57,60,69,70,79,87,101–103,106,112,117–121 ] Some groups have reported that charge injection is influenced by the hydrophilicity of films and the atmospheric moisture. [ 46,47,60,101–103 ] The effects of the injection time, [ 44,46,79,119 ] injection bias, [ 40,44,79,119 ] and the duration of the applied field [ 113 ] on the charge trapping processes have also been widely investigated. Maedler and Graaf investigated the relationship of trapped charges and the injection time and found that the quantity of trapped charges is nonlinearly dependent on the injection times.…”