3 years ago

Electric-Field-Controlled Dopant Distribution in Organic Semiconductors

Electric-Field-Controlled Dopant Distribution in Organic Semiconductors
Dongxiang Wang, Eric Mankel, Vipilan Sivanesan, Seth R. Marder, Stephen Barlow, Sebastian Beck, Wolfgang Kowalsky, Robert Lovrincic, Sebastian Hietzschold, Annemarie Pucci, Seon-Young Rhim, Lars Müller, Patrick Reiser
Stable electrical doping of organic semiconductors is fundamental for the functionality of high performance devices. It is known that dopants can be subjected to strong diffusion in certain organic semiconductors. This work studies the impact of operating conditions on thin films of the polymer poly(3-hexylthiophene) (P3HT) and the small molecule Spiro-MeOTAD, doped with two differently sized p-type dopants. The negatively charged dopants can drift upon application of an electric field in thin films of doped P3HT over surprisingly large distances. This drift is not observed in the small molecule Spiro-MeOTAD. Upon the dopants’ directional movement in P3HT, a dedoped region forms at the negatively biased electrode, increasing the overall resistance of the thin film. In addition to electrical measurements, optical microscopy, spatially resolved infrared spectroscopy, and scanning Kelvin probe microscopy are used to investigate the drift of dopants. Dopant mobilities of 10−9 to 10−8 cm2 V−1 s−1 are estimated. This drift over several micrometers is reversible and can be controlled. Furthermore, this study presents a novel memory device to illustrate the applicability of this effect. The results emphasize the importance of dynamic processes under operating conditions that must be considered even for single doped layers. The electric-field-controlled movement of dopants in organic semiconductors is investigated with electrical measurements, optical microscopy, and spatially resolved infrared spectroscopy. This study evaluates two p-type dopants in a polymer and small molecule host material and utilizes the movement to build a proof-of-concept memristive device by reversibly changing the overall conductivity of thin films.

Publisher URL: http://onlinelibrary.wiley.com/resolve/doi

DOI: 10.1002/adma.201701466

You might also like
Discover & Discuss Important Research

Keeping up-to-date with research can feel impossible, with papers being published faster than you'll ever be able to read them. That's where Researcher comes in: we're simplifying discovery and making important discussions happen. With over 19,000 sources, including peer-reviewed journals, preprints, blogs, universities, podcasts and Live events across 10 research areas, you'll never miss what's important to you. It's like social media, but better. Oh, and we should mention - it's free.

  • Download from Google Play
  • Download from App Store
  • Download from AppInChina

Researcher displays publicly available abstracts and doesn’t host any full article content. If the content is open access, we will direct clicks from the abstracts to the publisher website and display the PDF copy on our platform. Clicks to view the full text will be directed to the publisher website, where only users with subscriptions or access through their institution are able to view the full article.