Charge Transport and Conductance Switching of Redox-active Azulene Derivatives

التفاصيل البيبلوغرافية
العنوان: Charge Transport and Conductance Switching of Redox-active Azulene Derivatives
المؤلفون: Schwarz, Florian, Koch, Michael, Kastlunger, Georg, Berke, Heinz, Stadler, Robert, Venkatesan, Koushik, Loertscher, Emanuel
المصدر: English version: Angew. Chem. Int. Ed. 55, 11781 (2016), German version: Angew. Chem. 128, 11956 (2016)
سنة النشر: 2017
المجموعة: Condensed Matter
مصطلحات موضوعية: Condensed Matter - Mesoscale and Nanoscale Physics
الوصف: Azulene (Az) is a non-alternating, aromatic hydrocarbon composed of a five-membered, electron-rich and a seven-membered, electron-poor ring; an electron distribution that provides intrinsic redox activity. By varying the attachment points of the two electrode-bridging substituents to the Az centre, the influence of the redox functionality on charge transport is evaluated. The conductance of the 1,3 Az derivative is at least one order of magnitude lower than those of the 2,6 Az and 4,7 Az derivatives, in agreement with density functional theory (DFT) calculations. In addition, only 1,3 Az exhibits pronounced nonlinear current-voltage characteristics with hysteresis, indicating a bias-dependent conductance switching. DFT identifies the LUMO to be nearest to the Fermi energy of the electrodes, but to be an active transport channel only in the case of the 2,6 and the 4,7 Az derivatives, whereas the 1,3 Az derivative uses the HOMO at low and the LUMO+1 at high bias. In return, the localized, weakly coupled LUMO of 1,3 Az creates a slow electron-hopping channel responsible for the voltage-induced switching due to the occupation of a single MO.
Comment: 6 pages, 3 figures
نوع الوثيقة: Working Paper
DOI: 10.1002/anie.201605559
URL الوصول: http://arxiv.org/abs/1709.00277
رقم الأكسشن: edsarx.1709.00277
قاعدة البيانات: arXiv