Direct Evidence of Photoinduced Charge Transport Mechanism in 2D Conductive Metal Organic Frameworks

• DOI: 10.1021/jacs.0c09000
• Publication Date: 2020-11-23T23:26:31Z
• Authors: James Nyakuchena; Sarah Ostresh; Daniel Streater; Brian Pattengale; Jens Neu; Christian Fiankor; Wenhui Hu; Eli Diego Kinigstein; Jian Zhang; Xiaoyi Zhang; Charles A. Schmut...; Jier Huang
• Keywords: Chemistry; 540; 01 natural sciences; 0104 chemical sciences

Conductive metal organic frameworks (MOFs) represent a promising class of porous crystalline materials that have demonstrated potential in photo-electronics and photocatalytic applications. However, the lack fundamental understanding on charge transport (CT) mechanism as well correlation CT with their structure hampered further development. Herein, we report direct evidence 2D Cu-THQ MOFs temporal spatial behaviors carriers photoconductivity by combining three advanced spectroscopic methods, including time resolved optical X-ray absorption spectroscopy terahertz spectroscopy. In addition to Cu-THQ, Cu/Zn-THQ after incorporating Zn2+ guest was also examined uncover contribution through space pathway, presence redox inactive 3d10 is expected perturb long range in-plane CT. We show hot generated photoexcitation are highly mobile undergo fast localization lower energy state (cool carriers) electrons occupying Cu center holes ligands. The cool carriers, which super lifetime (>17 ns), responsible for long-term O-Cu-O motif negligible from interlayer ligand π-π stacking, incorporation significantly reduced photoconductivity. These unprecedented results not only demonstrate capability experimentally probe but provide important insight rational design photoelectronic