Highly Efficient One-Dimensional Triplet Exciton Transport in a Palladium–Porphyrin-Based Surface-Anchored Metal–Organic Framework

• DOI: 10.1021/acsami.9b03079
• Publication Date: 2019-04-02T16:19:03Z
• Authors: Michael Adams; Mariana Kozlowska; Nicolò Baroni; Michael Oldenburg; Rui Ma; Dmitry Busko; Andrey Turshatov; Ganapathi Emandi; Mathias O. Senge; Ritesh Haldar; Christof Wöll; G. Ulrich Nienhaus; Bryce S. Richards; Ian A. Howard
• Keywords: ddc:620; 570; Transient absorption; Thin films; Metal-organic frameworks; 540; DFT; 7. Clean energy; 01 natural sciences; 620; 0104 chemical sciences; Porphyrin; Engineering & allied operations; info:eu-repo/classification/ddc/620; Exciton transport; Electronic coupling

Efficient photon-harvesting materials require easy-to-deposit exhibiting good absorption and excited-state transport properties. We demonstrate an organic thin-film material system, a palladium–porphyrin-based surface-anchored metal–organic framework (SURMOF) thin film that meets these requirements. Systematic investigations using transient spectroscopy confirm triplets are very mobile within single crystalline domains; detailed analysis reveals triplet transfer rate on the order of 1010 s–1. The nature SURMOFs also allows thorough theoretical density functional theory. results reveal intermolecular exciton can be described by Dexter electron exchange mechanism is considerably enhanced virtual charge-transfer intermediates. On basis photophysical results, we predict diffusion lengths several micrometers in perfectly ordered, single-crystalline SURMOFs. In presently available samples, strong interactions excitons with domain boundaries present films limit length to diameter two-dimensional grains, which amount about 100 nm. Our high potential for light-harvesting applications.