题目： | Charge-Transfer Crystallites as Molecular Electrical Dopants |
作者： | Henry Mendez1,2,*, Georg Heimel1,*, Stefanie Winkler1,3, Johannes Frisch1,3, Andreas Opitz1, Katrein Sauer1, Berthold Wegner1, Martin Oehzelt1,3, Christian Rothel4, Steffen Duhm5,6, Daniel Tobbens7, Norbert Koch1,3,5 & Ingo Salzmann1,* |
单位： | 1Humboldt-Universitat zu Berlin, Institut fu¨r Physik and IRIS Adlershof, AG Supramolekulare Systeme, Brook-Taylor Stra e 6, 12489 Berlin, Germany. 2Departamento de Fısica, Pontificia Universidad Javeriana, Carrera 7, No. 43–82 Ed. 52 Of. 606, Bogota´, Colombia. 3Helmholtz-Zentrum Berlin fu¨r Materialien und Energie GmbH, Bereich Solarenergieforschung, Albert-Einstein-Straβe 15, 12489 Berlin, Germany. 4Institut fu¨r Festko¨rperphysik, Graz University of Technology, Petersgasse 16, Graz 8010, Austria. 5Jiangsu Key Laboratory for Carbon Based Functional Materials and Devices and Institute of Functional Nano and Soft Materials (FUNSOM), Soochow University, 199 Ren-Ai Road, Suzhou 215123, China. 6Soochow University-Western University Joint Centre for Synchrotron Radiation Research (SWC) and Collaborative Innovation Center of Suzhou Nano Science & Technology (NANO-CIC), Soochow University, 199 RenAi Road, Suzhou 215123, China. 7Helmholtz-Zentrum Berlin fu¨r Materialien und Energie GmbH—BESSY II, Abteilung Kristallographie, Albert-Einstein-Stra e 15, 12489 Berlin, Germany. |
摘要： | Ground-state integer charge transfer is commonly regarded as the basic mechanism of molecular electrical doping in both, conjugated polymers and oligomers. Here, we demonstrate that fundamentally different processes can occur in the two types of organic semiconductors instead. Using complementary experimental techniques supported by theory, we contrast a polythiophene, where molecular p-doping leads to integer charge transfer reportedly localized to one quaterthiophene backbone segment, to the quaterthiophene oligomer itself. Despite a comparable relative increase in conductivity, we observe only partial charge transfer for the latter. In contrast to the parent polymer, pronounced intermolecular frontier-orbital hybridization of oligomer and dopant in 1:1 mixed-stack co-crystallites leads to the emergence of empty electronic states within the energy gap of the surrounding quaterthiophene matrix. It is their Fermi–Dirac occupation that yields mobile charge carriers and, therefore, the co-crystallites—rather than individual acceptor molecules—should be regarded as the dopants in such systems. |
影响因子： | 10.742 |
分区情况： | 2区 |
链接： | http://www.nature.com/ncomms/2015/151006/ncomms9560/full/ncomms9560.html 责任编辑：向丹婷 |