Room-Temperature Self-Organizing Characteristics of Soluble Acene Field-Effect Transistors

Authors


  • This work was supported by a grant (F0004022-2007-23) from the Information Display R&D Center under the 21st Century Frontier R&D Program. We are also grateful for a grant (RTI04-01-04) from the Regional Technology Innovation Program of MOCIE, and for the support from the ERC Program of MOST/KOSEF (R11-2003-006-05004-0), POSTECH Core Research Program, the BK21 Program of the Ministry of Education and Human Resources Development of Korea. We are grateful to the Pohang Accelerator Laboratory for providing the 8C1 and 10C1 beamlines used in this study.

Abstract

We report on the room-temperature self-organizing characteristics of thin films of the organic small-molecule semiconductor triethylsilylethynyl-anthradithiophene (TES-ADT) and its effect on the electrical properties of TES-ADT-based field-effect transistors (FETs). The morphology of TES-ADT films changed dramatically with time, and the field-effect mobility of FETs based on these films increased about 100-fold after seven days as a result of the change in molecular orientation from a tilted structure in the as-prepared film to a well-oriented structure in the final film. We found that the molecular movement is large enough to induce a conformational change to an energetically stable state in spin-coated TES-ADT films, because TES-ADT has a low glass-transition temperature (around room temperature). Our findings demonstrate that organic small-molecule semiconductors that exhibit a low crystallinity immediately after spin-coating can be changed into highly crystalline structures by spontaneous self-organization of the molecules at room temperature, which results in improved electrical properties of FETs based on these semiconductors.

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