Monolayer Transistor Using a Highly Ordered Conjugated Polymer as the Channel

Abstract

Field-effect transistor structures based on polydiacetylene (PDA) derivatives have been fabricated. Monolayer channels of UV polymerized pentacosa-10,12-diynoic ethanolamide exhibit modulation of source-drain current on application of a gating voltage. Comparison of the two-dimensional crystal morphology of this material with several closely related derivatives that show no gating suggests that a high degree of alignment and order in the polymer chains is necessary for the observed transistor action.

From Monolayer to Multilayer N‐Channel Polymeric Field‐Effect Transistors with Precise Conformational Order

“…[7,8] Polydiacetylenes have also been used to fabricate monolayer FETs, again, with performance being far from ideal. [9] Although, charge transport behaviors of small-molecule-based n-channel FETs as a function of active layer thickness were shown previously, [10] no examples have been reported to date for polymer-based n-channel monolayer semiconductors. Recent studies have shown that n-type semiconducting polymers exhibit very attractive charge transport properties, [11] with electron mobilities of ∼0.2 cm 2 V −1 s −1 reported for the polymer poly{[N,N′-bis(2-octyldodecyl)-naphthalene-1,4,5,8-bis(dicarboximide)-2,6-diyl]-alt-5,5′-(2,2′-bithiophene)} (P(NDI2OD-T2), Polyera ActivInk N2200) in a top-gate FET architecture and using PMMA as gate dielectric.…”

From the bottom up: dimensional control and characterization in molecular monolayers

“…181 Polymerization creates linear polydiacetylene chains that terminate at domain edges or defects, with HOMO-LUMO gaps that decrease with increasing chain length, 154 and conductivities that increase substantially (up to 1000×) with iodine doping. 180 Films of polymerized pentacosa-10,12-diynoic ethanolamide exhibit source–drain modulation when a gate bias is applied, in contrast to less-ordered polymerized films, 182 suggesting the importance of aligning 1D features for applications in devices.…”

Atomic-scale analysis of polydiacetylene nanowires by scanning tunneling microscopy

“…Though desorption is clearly a problem for future devices, if the nanowires are in fact being picked up by the local probe, then it is possible that PDA-based devices not probed by STM would still work. This may explain the success of PDA-based transistors in recent reports [5,16]. It should also be noted that PDA nanowire desorption effects observed here can interfere with the observation of scanning tunneling spectroscopy (STS) data.…”

“…Furthermore, PDA nanowires can desorb due to the STM tip [4]. Understanding PDA nanowire behavior is important for applications such as PDA monolayer transistors [5]. Here we use STM to analyze PDA nanowires on highly-ordered pyrolytic graphite (HOPG) and molybdenum disulfide (MoS 2 ) in order to understand the influence of the substrate on the electronic behavior of these structures.…”