social linkedin box blue 32
social facebook box blue 32
social twitter box blue 32
social facebook box blue 32

Microspectroscopy techniques for mapping the opto-electronic properties of organic thin-film transistors


Solution processable organic field-effect transistors (OFETs) have recently reached a mature stage that preludes their adoption in a variety of commercial applications from light-weight, stretchable, large-area sensors to low-cost, flexible electronic circuits. The optimization of performances required for such applications demands a deep understanding of the device physics: with the aim to investigate the relationship between thin films micro-structure and charge transport properties, we developed a probing technique capable of providing local information regarding field and charge distribution along the channel of a working device. By coupling modulation spectroscopy techniques to a confocal microscope, we are able to image the opto-electronic properties of organic semiconductors with a lateral resolution of about 500 nm.

As we recently reported, exploiting Charge Modulation Microscopy it is possible to image the charge distribution inside the channel of an n-type organic transistor based on the high-mobility polymer poly{[ N , N' -bis(2-octyldodecyl)-naphthalene-1,4,5,8-bis(dicarboximide)-2,6-diyl]-alt-5,5'-(2,2'-bithiophene)} (Polyera's ActivInk™ N2200). Our method allows to directly probe buried layers in a transparent device and does not require highly controlled test conditions (e.g. ultrahigh-vacuum). Interestingly, we unveiled a sub-micrometer texture of charge modulation features along the channel of the transistor, which were attributed to the packing motif of the polymer chains in the nanometer-thick accumulation layer of the device. These important evidences provide us with a deeper insight in charge transport properties in a relevant class of semiconducting materials.

Related IIT publications
  • C. Sciascia, N. Martino, T. Schuettfort, B. Watts, G. Grancini, M. R. Antognazza, M. Zavelani-Rossi, C. R. McNeill, M. Caironi, "Sub-Micrometer Charge Modulation Microscopy of a High Mobility Polymeric n-Channel Field-Effect Transistor", Advanced Materials, 23, 5086–5090 (2011) DOI: 10.1002/adma.201102410
  • C. Sciascia, M. Celebrano, M. Binda, D. Natali, G. Lanzani, J. R. Cabanillas-Gonzalez, "Electric field and charge distribution imaging with sub-micron resolution in an organic Thin-Film Transistor", Organic Electronics, 13, 66– 70 (2012) DOI: 10.1016/j.orgel.2011.09.023
Center for Nano Science and Technology Via Pascoli 70/3, 20133 Milano, Italia Tel: +39 02 2399 9867 – 9877 Fax: +39 02 2399 9866
Copyright © 2015 Istituto Italiano di Tecnologia - Tel: +39 010 71781. C.F. 97329350587 - P.I. 09198791007
Try our new site and tell us what you think
Take me there
Privacy and Data Protection

IIT's website uses the following types of cookies: browsing/session, analytics, functional and third party cookies. Users can choose whether or not to accept the use of cookies and access the website. By clicking on "Further Information", the full information notice on the types of cookies will be displayed and you will be able to choose whether or not to accept them whilst browsing on the website.

Further Information I Understand