Molecular Origin of the Charge Carrier Mobility in Small Molecule Organic Semiconductors

作者：Friederich Pascal; Meded Velimir; Poschlad Angela; Neumann Tobias; Rodin Vadim; Stehr Vera; Symalla Franz; Danilov Denis; Luedemann Gesa; Fink Reinhold F; Kondov Ivan; von Wrochem Florian; Wenzel Wolfgang^*

来源：Advanced Functional Materials, 2016, 26(31): 5757-5763.

DOI：10.1002/adfm.201601807

• charge transport
• materials design
• multiscale modeling
• organic electronics

Small-molecule organic semiconductors are used in a wide spectrum of applications, ranging from organic light emitting diodes to organic photovoltaics. However, the low carrier mobility severely limits their potential, e.g., for large area devices. A number of factors determine mobility, such as molecular packing, electronic structure, dipole moment, and polarizability. Presently, quantitative ab initio models to assess the influence of these molecule-dependent properties are lacking. Here, a multiscale model is presented, which provides an accurate prediction of experimental data over ten orders of magnitude in mobility, and allows for the decomposition of the carrier mobility into molecule-specific quantities. Molecule-specific quantitative measures are provided how two single molecule properties, the dependence of the orbital energy on conformation, and the dipole-induced polarization determine mobility for hole-transport materials. The availability of first-principles based models to compute key performance characteristics of organic semiconductors may enable in silico screening of numerous chemical compounds for the development of highly efficient optoelectronic devices.

• 出版日期2016-8