An Analysis of Regioregular Poly(3-hexylthiophene-2,5-diyl) Using Kelvin Probe Force Microscopy
Date
2016-07-01
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Abstract
There is a constant push for innovative applications of electronics. The traditional
materials used to construct these devices, such as inorganic silicon, are expensive
and brittle. Semiconducting conjugated polymers offer an exciting alternative to
manufacturing materials, as they are flexible and affordable to mass-produce. A
significant amount of work has been done in the field of organic electronics since
conjugated polymers were first found to be conductive several decades ago. The
approaches to studying the characteristics of these materials are varied including
simulations, dielectric spectroscopy, electrostatic force microscopy, and scanning
Kelvin probe microscopy. Groups have looked at how to evaluate charge carrier
mobility, threshold voltage, trapping/detrapping processes and time scales, the
shape and behavior of the density of states, and pinch off voltage. The focus of our
interest is on understanding charge carrier transport, mobility, and the effects of
trap states of these characteristics. This is studied through an unconventional use
of KPFM as well as standard IV characterization. While other research groups have
previously modeled trap states, we hope to understand how different manufacturing
processes passivate traps to improve mobility and how the behavior of trap states
change at different back gate voltages.
This work will discuss our approach to studying P3HT, a polymer of choice
for its good optoelectronic properties. We use atomic force microscopy to record
traditional IV transistor curves as well as use KPFM to scan across the transistor
channel and record the behaviors of charge carriers at a single point on the device
Description
Keywords
P3HT, physics, thin films, FET, KPFM, Kelvin Probe Force Microscopy