• Organic electronics are devices such as Solar Cells, TV’s, and cell phone screens that utilize organic materials. The use of Organic materials offer many exciting advantages including mechanical flexibility and low cost of materials and manufacturing.

Introduction

• Photoswitching molecules change conformation when irradiated with discrete wavelengths of light. Doping the organic semiconductors of OFETs with photoswitchable molecules can enable multifunctional transistors [3].

• Using optical analysis we aim to study the dependence of switching of a pyrrolesubstituted aurone (Py, fig. 1) on the surrounding environment to determine the viability of this molecule for use in light-switchable OFETs.

• Our long term goal is to examine the photoswitching of Py in an organic semiconductor and the effects of this switching on transistor properties.

• Py studied in thick and thin Py/PMMA polymer films (.04785% Py by weight)

• Created predominantly E isomer samples by irradiating molecules with 405nm light for 120s

• Created Predominantly Z Isomers by irradiating molecules with 469nm light for 300s

Methods

Results

Conclusion

• Py can be photoisomerized in thick and thin polymer films

• Py’s conversion from Z to E occurs much faster relative to the E to Z conversion

References[1] Flexible Organic Solar Modules. N.d. Photograph. Idw-online.de Karin Schneider. Web.

[2]Organic Field Effect Transistor N.d. Photograph. bo.ismn.cnr.it/ Web.

[3] Emanuele Orgiu, et al. “Optically switchable transistor via energy-level phototuning in a bicomponent organic semiconductor.” Nature Chemistry vol. 4 (2012)

[4] Loew, Maura. “CHARACTERIZATION OF AN AURONE BEARING A PYRROLE SUBSTITUENT” Ch. 4 Ph.D Thesis

Acknowledgements

1. Department of Physics - Binghamton University – State University of New York

James Duffy1, Tong Yang1, Maura Loew2, Susan Bane2, Jeffrey Mativetsky1

Optically Switching Organic Field Effect Transistors

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• Photoswitching of Py in thin polymer films examined in real time by collecting the intensity of each isomer’s emission peak while irradiating for conformational change.

Thin Film Kinetics

Irradiating at 469nm, collecting emission at 497nmIrradiating at 405nm, collecting Emmision at 446nm

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[1]

• A key device in Organic Electronics is the Organic Field Effect Transistor (OFET).

Thick Film Emission

[2]

Thin Film Emission

• After irradiation the samples exhibited distinct emission spectra indicative of good photoswitching.

• The photoswitching of Py is maintained in thin films.

Future Goals

• Study optical properties of Py in TIPS-Pentacene organic semiconductor

• Examine photoswitching effects of Py on OFET with Py doped organic semiconductor

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Photoisomerization of Py[4]

Fig. 1

Predominantly E

Predominantly Z

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• Dr. Scott Handy - Supplier of Py

• Takian Chio

• Alexander Haruk

Goals

2. Department of Chemistry – Binghamton University – State University of New York