Dry Single-Crystal Device Fabrication and Contact Engineering for Air- and Solvent-Sensitive Two-Dimensional Metal–Organic Frameworks

Two-dimensional metal–organic frameworks (2D MOFs) feature structural tunability and electronic confinement for quantum, electronic, and spintronic applications. However, the fabrication of single-crystal devices and the investigation of intrinsic electrical and magnetic properties remain challenging, largely because of the small crystallite size and high environmental sensitivity. Here, we develop a micro-/nanofabrication strategy in an oxygen- and solvent-free environment, enabling exfoliation, dry-transfer, and bottom-contact device fabrication of a chemically sensitive 2D MOF, [N(CH 3 ) 4 ] 2 [Fe 2 CA 3 ]·7DMF (H 2 CA = chloranilic acid), which lacks interlayer π–π stacking and exhibits an interlayer distance of 1 nm. Au electrodes with a 4-contact probe configuration achieved the lowest contact resistance and Ohmic contact at room temperature, significantly enhancing electrical conductivity. Variable-temperature electrical characterization revealed semiconductor behaviors. This approach provides a reliable route for exploring the intrinsic properties of 2D MOFs, accelerates their practical use in low-dimensional quantum systems, and establishes a strategy for constructing micro-/nanodevices with other sensitive low-dimensional materials.