WEB Crystal engineering of metal-organic framework films for tailoring optical and semiconducting propertiesThursday (24.09.2020) 10:40 - 10:55 M: Modelling and Simulation 1 Part of:
Due to their vast chemical composition space, metal organic frameworks (MOFs) have emerged as a versatile class of functional materials with tunable properties for various applications. This is achieved by the modulation and tailoring of the molecular structure and organization of the structural components by multiscale modelling and layer-by-layer synthesis. Here, we show the use of multiscale models, that combine structural simulations with electronic structure calculations, to explain the origin of the photophysical and semiconducting behavior of MOF films as the function of their nano/microscale morphology.
Using the density functional theory formalism and our in-house developed ab initio method, we investigate highly efficient excited-state energy transport properties of porphyrin surface-anchored metal-organic frameworks (SURMOFs) , enhancement of photoconduction of MOF upon embedding of fullerene  and pronounced green electroluminescence of thermally-activated delayed fluorescence (TADF) triggered SURMOF films . We predict the charge transport and mobility in polycyclic aromatic hydrocarbons as a function of the type of the organic linker in MOF and show enhancement of the material conductivity as derived from their spatially ordered structure. Finally, we demonstrate the charge transport anisotropy through the detailed analysis of the charge transfer rates.
Together with experimental observations, we prove that ab initio calculations enable valuable predictions of new promising candidates for emitting and semiconducting organic materials made in spatially ordered fashion in the SURMOF. Our data demonstrates the feasibility of MOF-based crystal engineering approaches that can be universally applied to tailor the materials properties.
 M. Adams, M. Kozlowska, N. Baroni, M. Oldenburg, R. Ma, D. Busko, A. Turshatov, G. Emandi, M. O.Senge, R. Haldar, C. Wöll, G. U. Nienhaus, B. S. Richards, I. A. Howard, ACS Appl. Mater. Interfaces, 2019, 11, 15688-15697.
 X. Liu, M. Kozlowska, T. Okkali, D. Wagner, T. Higashino, G. Brenner-Weiß, S. M. Marschner, Z. Fu, Q. Zhang, H. Imahori, S. Bräse, W. Wenzel, C. Wöll, L. Heinke, Angew. Chem. Int. Ed, 2019, 58, 9590-9595.
 R. Haldar, M. Jakoby, M. Kozlowska, M. R. Khan, H. Chen, Y. Pramudya, B. S. Richards, L. Heinke, W. Wenzel, F. Odobel, S. Diring, I. A. Howard, U. Lemmer, C. Wöll, submitted.