Metal–organic frameworks (MOFs) are known for their high porosity and structural versatility. Thanks to these properties, they are considered promising for use in electronics. One existing limitation, however, has been their low electrical conductivity, which restricts their application.
Researchers at the Karlsruhe Institute of Technology (KIT), in collaboration with teams from Göttingen, Berlin, and São Paulo, have developed a thin MOF film with the help of an AI- and robot-assisted laboratory that achieves metallic conductivity – a major breakthrough for electronic and energy-related applications.
MOFs are composed of metallic nodes and organic linkers and are used, for example, in catalysis, separation, and gas storage. The key innovation: for the first time, a thin MOF film has been produced that actually behaves like a metal.
Technical Implementation
"The cause of the low electrical conductivity lies in defects such as grain boundaries between crystalline domains," explains Professor Christof Wöll, Head of the IFG at KIT. "Such structural defects hinder electron transport. With our new manufacturing process, we have significantly reduced the density of these defects."
In the automated laboratory, the MOF Cu₃(HHTP)₂ was optimized in thin film form. Thanks to precise AI control, crystallinity and domain size could be ideally adjusted – with the result: conductivity of over 200 S/m at room temperature, and even higher at –173 °C, confirming metallic behavior.
Typically, MOFs exhibit low conductivity due to electron hopping (red curve), which decreases significantly when cooled. Not so with these highly ordered MOFs: their conductivity increases upon cooling (green curve) – a hallmark of metallic behavior.
New Research Opportunities
Theoretical studies indicate that Cu₃(HHTP)₂ possesses Dirac cones – an electronic structure similar to that of graphene.
"This opens up entirely new possibilities for experimentally investigating unusual transport phenomena," says Wöll.
Potential and Outlook
The combination of automated synthesis, predictive characterization, and theoretical modeling creates new opportunities: from sensor technology and quantum materials to customized functional materials with specific electronic properties.
Publication Details
Original Publication (Open Access):
Chatrawee Scheiger et al.: Dirac-cone induced metallic conductivity in Cu₃(HHTP)₂: high-quality MOF thin films fabricated via ML-driven robotic synthesis. Materials Horizons, 2025.
