Recent development of dopant induced solubility control (DISC) patterning of polymer semiconductors has enabled direct‐write optical patterning of poly‐3‐hexylthiophene (P3HT) with diffraction limited resolution. Here, the optical DISC patterning technique to the most simple circuit element, a wire, is applied. Optical patterning of P3HT and P3HT doped with the molecular dopant 2,3,5,6‐tetrafluoro‐7,7,8,8‐tetracyanoquinodimethane (F4TCNQ) wires with dimensions of 20–70 nm thickness, 200–900 nm width, and 40 μm length is demonstrated. In addition, optical patterning of wire patterns like “L” bends and “T” junctions without changing the diameter or thickness of the wires at the junctions is demonstrated. The wires themselves show up to 0.034 S cm‐1conductance when sequentially doped. It is also demonstrated that a P3HT nanowire can be doped, de‐doped, and re‐doped from solution without changing the dimension of the wire. The combined abilities to optically pattern and reversibly dope a polymer semiconductor represents a full suite of patterning steps equivalent to photolithography for inorganic semiconductors.
Organic–inorganic hybrids offer great promise as solution‐processable thermoelectric materials. However, they have struggled to surpass the performance of their rigid inorganic counterparts due, in part, to a lack of synthetic control and limited understanding of how inorganic nanostructure dimensions impact overall charge transport. While it has been hypothesized that length, diameter, and aspect ratio (AR) all impact electronic transport in hybrid nanowires, the field lacks clarity on the relative role of each. In this study, the experimental parameter of ligand molecular weight (MW) is investigated as a synthetic knob for modulating nanowire dimensions, as well as the deconvolution of nanowire length versus diameter impacts on electron transport. By increasing ligand MW, larger nanowire AR dispersions occur and an optimal power factor of ≈130 μWm−1K−2is achieved for a modest AR of 73. Power factors of this magnitude are thought to only be achievable in ultrahigh AR systems; representing a 183% increase in performance over literature reports with similar AR. Additionally, nanowire diameter is demonstrated to be a far more sensitive parameter for enhancing performance than modulating length. This study provides improved fundamental insight into rational synthetic design avenues for future enhancements in the performance of hybrid materials.more » « less
- NSF-PAR ID:
- Publisher / Repository:
- Wiley Blackwell (John Wiley & Sons)
- Date Published:
- Journal Name:
- Advanced Electronic Materials
- Medium: X
- Sponsoring Org:
- National Science Foundation
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