Thermal vibrations and the dynamic disorder they create can detrimentally affect the transport properties of van der Waals bonded molecular semiconductors. The low-energy nature of these vibrations makes it difficult to access them experimentally, which is why we still lack clear molecular design rules to control and reduce dynamic disorder. In this study we discuss the promising organic semiconductors rubrene, 2,7-dioctylbenzothieno[3,2-b]benzothio-phene and 2,9-di-decyl-dinaphtho-[2,3-b:20,30-f]-Thieno-[3,2-b]-Thiophene in terms of an exceptionally low degree of dynamic disorder. In particular, we analyse diffuse scattering in transmission electron microscopy, to show that small molecules that have their side chains attached along the long axis of their conjugated core are better encapsulated in their crystal structure, which helps reduce large-Amplitude thermal motions. Our work provides a general strategy for the design of new classes of very high mobility organic semiconductors with a low degree of dynamic disorder.
|State||Published - Feb 22 2016|
Bibliographical noteFunding Information:
S.I. acknowledges funding from the EPSRC, the Winton Programme for the Physics of Sustainability and the Cambridge Home and EU scholarship scheme (CHESS). A.E. acknowledges the Seventh Framework Programme of the European Commission: ESTEEM2 (contract number 312483) as well as the Royal Society. G.S. acknowledges postdoctoral fellowship support from the Wiener-Anspach Foundation. We acknowledge the support of Nippon Kayaku in providing the materials C8-BTBT and C10-DNTT. We acknowledge Dr John Morrison for synthesis of TMTES-P and Marie Beatrice for her work that resulted in the thin-film structure of TMTES-P. We acknowledge Audrey Richard and Christian Ruzié for the synthesis of 2,7-di-tertbutylbenzothieno[3,2– b]benzothiophene and bis(trimethylsilyl)benzothieno[3,2–b]benzothiophene.
ASJC Scopus subject areas
- Chemistry (all)
- Biochemistry, Genetics and Molecular Biology (all)
- Physics and Astronomy (all)