10.1021/nn4064067.s001
Thomas J. Dawidczyk
Thomas J.
Dawidczyk
Josué F. Martínez Hardigree
Josué
F. Martínez Hardigree
Gary L. Johns
Gary L.
Johns
Recep Ozgun
Recep
Ozgun
Olivia Alley
Olivia
Alley
Andreas G. Andreou
Andreas G.
Andreou
Nina Markovic
Nina
Markovic
Howard E. Katz
Howard E.
Katz
Visualizing and Quantifying Charge Distributions Correlated to Threshold Voltage Shifts in Lateral Organic Transistors
American Chemical Society
2014
charge
polymer gate material
Lateral Organic TransistorsLateral
OFET gate material
OSC
PMMA
surface voltage
PS
gate material interfaces
scanning Kelvin probe microscopy
shift
Quantifying Charge Distributions Correlated
surface voltage maps
transistor
surface voltage variation
SKPM
bias stress
Threshold Voltage Shifts
VT
2014-03-25 00:00:00
Journal contribution
https://acs.figshare.com/articles/journal_contribution/Visualizing_and_Quantifying_Charge_Distributions_Correlated_to_Threshold_Voltage_Shifts_in_Lateral_Organic_Transistors/2312341
Lateral organic field-effect transistors (OFETs), consisting of a polystyrene (PS) polymer gate material and a pentacene organic semiconductor (OSC), were electrically polarized from bias stress during operation or in a separate charging step, and investigated with scanning Kelvin probe microscopy (SKPM) and current–voltage determinations. The charge storage inside the polymer was indicated, without any alteration of the OFET, as a surface voltage with SKPM, and correlated to a threshold voltage (<i>V</i><sub>T</sub>) shift in the transistor operation. The SKPM method allows the gate material/OSC interface of the OFET to be visualized and the surface voltage variation between the two gate material interfaces to be mapped. The charge distribution for three samples was derived from the surface voltage maps using Poisson’s equation. Charge densities calculated this way agreed with those derived from the <i>V</i><sub>T</sub> shifts and the lateral gate-OSC capacitance. We also compared the behavior of two other polymers with PS: PS accepted the most static charge in its entire volume, poly(2-trifluoromethylstyrene) (F-PS) had the most stability to bias stress, and poly(methyl methacrylate) (PMMA) showed the most leakage current and least consistent response to static charging of the three polymers. This work provides a clear demonstration that surface voltage on a working OFET gate material can be related to the quantity of static charge responsible for bias stress and nonvolatility in OFETs.