Fabrication of Single Metal–Organic Framework Crystal Devices to Inform Energy Conversion Platforms

Stimulus-responsive metal–organic frameworks (MOFs) are compelling candidates for the active components of sensors, actuators, low-power electronics, and energy conversion platforms. However, strategies to precisely integrate single MOF crystals into devices, a crucial condition for fully exploiting their potential in high-performance and energy applications, are lacking. Here, we provide a primer on best practices in the fabrication of high quality devices from single MOF crystals. We discuss how to synthesize and configure MOFs for integration into devices, identify optimal lithography conditions, and define contacts to and measure devices to extract the maximum insight into the transport physics of these materials. Using a MOF composed of Mo2(isonicotinate)4 clusters as an exemplar, we apply these fabrication protocols to prepare two-terminal and three-terminal field-effect transistor devices. Measurements of these devices reveal the MOF to have a conductivity of ∼1 mS cm–1, a p-type behavior, and an underlying conductance anisotropy, all of which directly reflect the mixed valency and unique topology of the MOF. Our efforts seek to provide a more efficient route toward fabricating MOF-based devices and, by so doing, aim to advance the community's understanding of transport physics in MOFs and to inform how best to integrate them into next-generation energy conversion and storage platforms.