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Abstract Organic semiconductors have sparked interest as flexible, solution processable, and chemically tunable electronic materials. Improvements in charge carrier mobility put organic semiconductors in a competitive position for incorporation in a variety of (opto‐)electronic applications. One example is the organic field‐effect transistor (OFET), which is the fundamental building block of many applications based on organic semiconductors. While the semiconductor performance improvements opened up the possibilities for applying organic materials as active components in fast switching electrical devices, the ability to make good electrical contact hinders further development of deployable electronics. Additionally, inefficient contacts represent serious bottlenecks in identifying new electronic materials by inhibiting access to their intrinsic properties or providing misleading information. Recent work focused on the relationships of contact resistance with device architecture, applied voltage, metal and dielectric interfaces, has led to a steady reduction in contact resistance in OFETs. While impressive progress was made, contact resistance is still above the limits necessary to drive devices at the speed required for many active electronic components. Here, the origins of contact resistance and recent improvement in organic transistors are presented, with emphasis on the electric field and geometric considerations of charge injection in OFETs.
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Top-contact organic electrochemical transistors
Organic electrochemical transistors (OECTs) transduce ionic into electric signals, which makes them a promising candidate for a wide range of bio-electronic applications. However, despite their promise, the influence of their device geometry on performance is still not fully understood. Here, two different device geometries—top contact and bottom contact OECTs—are compared in terms of their contact resistance, reproducibility, and switching speed. It is shown that bottom contact devices have faster switching times, while their top-contact counterparts are superior in terms of slightly reduced contact-resistance and increased reproducibility. The origin of this trade-off between speed and reproducibility is discussed, which provides optimization guidelines for a particular application.
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- Award ID(s):
- 1750011
- PAR ID:
- 10597308
- Publisher / Repository:
- American Institute of Physics
- Date Published:
- Journal Name:
- AIP Advances
- Volume:
- 12
- Issue:
- 4
- ISSN:
- 2158-3226
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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