Face-to-Face Growth of Wafer-Scale 2D Semiconducting MOF Films on Dielectric Substrates

The preparation of large-area 2D conductive metal-organic framework (MOF) films remains highly desirable but challenging. Here, inspired by the capillary phenomenon, a face-to-face confinement growth method to grow conductive 2D Cu₂ (TCPP) (TCPP = meso-tetra(4-carboxyphenyl)porphine) MOF films on dielectric substrates is developed. Trace amounts of solutions containing low-concentration Cu²⁺ and TCPP are pumped cyclically into a micropore interface to produce this growth. The crystal structures are confirmed with various characterization techniques, which include high-resolution atomic force microscopy and cryogenic transmission electron microscopy (Cryo-TEM). The Cu₂ (TCPP) MOF film exhibit an electrical conductivity of ≈0.007 S cm^-1 , which is approximately four orders of magnitude higher than other carboxylic-acid-based MOF materials (10^-6 S cm^-1 ). Other wafer-scale conductive MOF films such as M₃ (HHTP)₂ (M = Cu, Co, and Ni; HHTP = 2,3,6,7,10,11-triphenylenehexol) can be produced utilizing this strategy and suggests this method has widescale applicability potential.