liu.seSearch for publications in DiVA
Change search
ReferencesLink to record
Permanent link

Direct link
Double-Gate Light-Emitting Electrochemical Transistor: Confining the Organic p-n Junction
Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, The Institute of Technology. null.
Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, The Institute of Technology. null.
Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, The Institute of Technology. null.ORCID iD: 0000-0003-4791-4785
2013 (English)In: Journal of the American Chemical Society, ISSN 0002-7863, E-ISSN 1520-5126, Vol. 135, no 33, 12224-12227 p.Article in journal (Refereed) Published
Abstract [en]

In conventional light-emitting electrochemical cells (LECs), an off-centered p-n junction is one of the major drawbacks, as it leads to exciton quenching at one of the charge-injecting electrodes and results in performance instability. To combat this problem, we have developed a new device configuration, the double-gate light-emitting electrochemical transistor (DG-LECT), in which the location of the light-emitting p-n junction can be precisely defined via the position of the two gate terminals. Based on a planar LEC structure, two gate electrodes made from an electrochemically active conducting polymer are employed to predefine the p- and n-doped area of the light-emitting polymer. Thus, a p-n junction is formed in between the p-doped and n-doped regions. We demonstrate a homogeneous and centered p-n junction as well as other predefined junction patterns in these DG-LECT devices. Additionally, we report an electrical model that explains the operation of the DG-LECTs. The DG-LECT device provides a new tool to study the fundamental physics of LECs, as it dissects the key working process of LEC into decoupled p-doping, n-doping, and electroluminescence.

Place, publisher, year, edition, pages
American Chemical Society , 2013. Vol. 135, no 33, 12224-12227 p.
National Category
Engineering and Technology
URN: urn:nbn:se:liu:diva-97661DOI: 10.1021/ja407049bISI: 000323536100019OAI: diva2:649986

Funding Agencies|Swedish Foundation for Strategic Research (OPEN)||European Regional Development Fund through Tillvaxtverket (PEA-PPP)||VINNOVA|2012-01607|Knut and Alice Wallenberg Foundation||Onnesjo Foundation||

Available from: 2013-09-19 Created: 2013-09-19 Last updated: 2015-05-06
In thesis
1. Light-Emitting Electrochemical Transistors
Open this publication in new window or tab >>Light-Emitting Electrochemical Transistors
2014 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

Since the discovery of conductive polymers in 1977, the implementation of organic conjugated materials in electronic applications has been of great interest in both industry and academia. The goal of organic electronics is to realize large-area, inexpensive and mechanically-flexible electronic applications.

Organic light emitting diodes (OLEDs), as the first commercial product made from organic conjugated polymers, have successfully demonstrated that organic electronics can make possible a new generation of modern electronics. However, OLEDs are highly sensitive to materials selection and requires a complicated fabrication process. As a result, OLEDs are expensive to fabricate and are not suitable for low-cost printing or roll-to-roll process.

This thesis studies an alternative to OLEDs: light-emitting electrochemical cells (LECs). The active materials in an LEC consist of a conjugated light-emitting polymer (LEP) and an electrolyte. Taking advantage of electrochemical doping of the LEP, an LEC features an in-situ formed emissive organic p-n junction which is easy to fabricate. We aim to control the electrochemical doping profile by employing a “gate” terminal on top of a conventional LEC, forming a lightemitting electrochemical transistor (LECT). We developed three generations of LECTs, in which the position of the light-emitting profile can be modified by the voltage applied at the gate electrode, as well as the geometry of the gate materials. Thus, one can use this structure to achieve a centered light-emitting zone to maximize the power-conversion efficiency. Alternatively, LECTs can be used for information display in a highly integrated system, as it combines the simultaneous modulation of photons and electrons.

In addition, we use multiple LECs to construct reconfigurable circuits, based on the reversible electrochemical doping. We demonstrate an LEC-array where several different circuits can be created by forming diodes with different polarity at different locations. The thereby formed circuitry can be erased and turned into circuitry with other functionality. For example, the diodes of a digital AND gate can be re-programmed to form an analogue voltage limiter. These reprogrammable circuits are promising for fully-printed and large-area reconfigurable circuits with facile fabrication.

Place, publisher, year, edition, pages
Linköping: Linköping University Electronic Press, 2014. 57 p.
Linköping Studies in Science and Technology. Dissertations, ISSN 0345-7524 ; 1582
National Category
Natural Sciences
urn:nbn:se:liu:diva-104925 (URN)10.3384/diss.diva-104925 (DOI)978-91-7519-382-3 (print) (ISBN)
Public defence
2014-03-21, K2, Kåkenhus, Campus Norrköping, Linköpings universitet, Norrköping, 10:15 (English)
Available from: 2014-03-03 Created: 2014-03-03 Last updated: 2015-05-06Bibliographically approved

Open Access in DiVA

No full text

Other links

Publisher's full text

Search in DiVA

By author/editor
Liu, JiangEngquist, IsakBerggren, Magnus
By organisation
Physics and ElectronicsThe Institute of Technology
In the same journal
Journal of the American Chemical Society
Engineering and Technology

Search outside of DiVA

GoogleGoogle Scholar
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

Altmetric score

Total: 320 hits
ReferencesLink to record
Permanent link

Direct link