Flexible, ambipolar organic field-effect transistors based on the solution-processed films of octanaphthoxy-substituted bis(phthalocyaninato) europium

• A new sandwich-type bis(phthalocyaninato) europium complex was synthesized.
• First example to fabricate flexible OFETs by a simple quasi–Langmuir–Shäfer method.
• Good ambipolar transport for both holes and electrons has been obtained.

A new sandwich-type bis(phthalocyaninato) europium complex [Pc(OAr)8]Eu[Pc(OAr)8] [Pc(OAr)8 = 2,3,9,10,16,17,23,24-octanaphthoxy phthalocyanine], was synthesized and fabricated into organic field-effect transistors devices on a flexible plastic substrate by using a simple solution-based quasi–Langmuir–Shäfer method. Ambipolar transport has been obtained in [Pc(OAr)8]Eu[Pc(OAr)8]-based thin film transistors with the carrier mobilities to 0.10 cm2 V−1 s−1 for holes and 0.01 cm2 V−1 s−1 for electrons, respectively. The energy levels of the highest occupied molecular orbital (−4.63 eV) and the lowest unoccupied molecular orbital (−3.41 eV) were obtained based on electrochemical studies of this double-decker complex. These values just simultaneously meet the energy levels required for p-type and n-type natures of organic semiconductors, suggesting the ambipolar organic semiconducting nature of this double-decker complex. Organized film microstructures and J-type molecular stacking mode for the double-decker complex in the quasi–Langmuir–Shäfer film are revealed. This study constitutes the first attempt to fabricate low-cost, flexible ambipolar phthalocyanine-based organic field-effect transistors by using simple solution-processing methods.

Flexible, ambipolar OFETs based on the solution-processed QLS films of a new bis(phthalocyaninato) europium complex are obtained with the carrier mobilities of 0.10 cm2 V−1 s−1 for holes and 0.01 cm2 V−1 s−1 for electrons, respectively.Figure optionsDownload as PowerPoint slide