Metal-organic frameworks (MOFs) carry a huge potential with regard to assembling different types of function organic and metal-organic molecules into multifunctional,hybrid, molecular solids. The field is presently getting quite mature, as demonstrate by several applications exploiting the electrical, electronic and photophysical properties of this rich class of porous, crystalline materials [1]. Recent examples are MOF-based electrochemical [2,3], photo-electrochemical [4] and photovoltaic devices [5,6], as well as photon-upconversion [7]. We have developed a layer-by-layer method to produce well-defined, highly oriented and monolithic MOF thin films supported on different types of surfaces, also referred to as SURMOFs [1]. This procedure in particular allows the fabrication of hetero-multilayers. The fabrication of such well-defined model systems will be described, as well as the results of detailed, multi-technique investigations of electrical [8] and photophysical properties exhibited by empty and loaded MOFs, including cyclic voltammetry, atomic force microscopy, quartz crystal microbalance and UV-Vis spectroscopy. We will discuss the huge size of the chemical space spanned by MOFs can propose that by loading MOFs with nanoparticles or quantum dots the potential is further extended. SURMOFs offer particular advantages in this context, since the loading can be integrated in the layer-by-layer method, offering the potential to fabricate hetero-mulitlayers.

References:

[1] J. Liu, Ch. Wöll, Chem. Soc. Rev. 46, 5681 (2017)

[2] A. Dragässer, O. Shekhah, O. Zybaylo, C. Shen, M. Buck, Ch. Wöll, D. Schlettwein, Chem. Comm., 48, 663 (2012)

[3] J. Liu, M. Paradinas, L. Heinke, M. Buck, C. Ocal, V. Mugnaini, Ch. Wöll
Chem.Elektro.Chem., 3, 713 (2016)

[4] Lu Ye, J. Liu, Y. Gao, Ch. Gong, M. Addicoat, Th. Heine, Ch. Wöll, L. Sun, Mater. Chem. A, 4, 15320, (2016)

[5] J. Liu, W. Zhou, J. Liu, I. Howard, G. Kilibarda, S. Schlabach, D. Coupry, M. Addicoat, S. Yoneda, Y. Tsutsui, T. Sakurai, S. Seki, Zh. Wang, P. Lindemann, E. Redel, Th. Heine, Ch. Wöll, Angew. Chemie Intl. Ed., 54, 7441 (2015)

[6] J. Liu, W. Zhou, J. Liu, Y. Fujimori, T. Higashino, H. Imahori, X. Jiang, J. Zhao, T. Sakurai, Y. Hattori, W. Matsuda, Shu Seki, S. K. Garlapati, S. Dasgupta, E. Redel, L. Sun, Ch. Wöll, Journal of Mat. Chem. A, 4, 12739 (2016)

[7] M. Oldenburg, A. Turshatov, D. Busko, S. Wollgarten, M. Adams, N. Baroni, A. Welle, E. Redel, Ch. Wöll, B. S. Richards, I. A. Howard, Adv. Mater., 28, 8477 (2016)

[8] J. Liu, T. Wächter, A. Irmler, P.G. Weidler, H. Gliemann, F. Pauly, V. Mugnaini, M. Zharnikov, Ch. Wöll, ACS Applied Materials & Interfaces, 7, 9824, (2015)