Thin Films of MOF-on-Guest@MOF: A Simple Strategy of Designing Electronic Heterostructures

Depositing thin films of pristine metal-organicframework(MOF) on top of a lattice-matched and molecularly doped MOF couldprovide a new path for generating electronic heterostructures of MOFswith well-defined interfaces. Herein, the Cu3BTC2 (top-layer)/TCNQ@Cu3BTC2 (bottom-layer) systemis fabricated by sequential deposition on a functionalized Au substrate,and clear-cut rectification of electrical current across the thinfilm was observed at room-temperature. Interestingly, the electricalcurrent rectification ratio (RR) was found to be significantly influencedby the effect of temperature (400 K), resulting in a remarkable figurein the domain of MOFs. Electronic heterostructuresof pristine and molecularlydoped MOFs was fabricated upon depositing Cu3BTC2 thin film on top of TCNQ@Cu3BTC2 thin filmon a functionalized Au substrate via a layer-by-layer (LbL) technique,and remarkably, the current rectification ratio was found to be & SIM;10(5) at 300 K, which was further enhanced by an order of magnitudeupon increasing the temperature to 400 K. Such heterostructured thinfilms of MOFs with well-defined electronic interfaces are promisingfor device applications.

Automated summary

Depositing thin films of pristine and molecularly doped metal-organic frameworks (MOFs) on a lattice-matched substrate could generate electronic heterostructures with well-defined interfaces. In this study, a Cu3BTC2 (top-layer)/TCNQ@Cu3BTC2 (bottom-layer) system was fabricated on a functionalized Au substrate, and clear rectification of electrical current was observed at room temperature. The current rectification ratio was found to be influenced by temperature, with significant improvement at 400 K. These heterostructured thin films of MOFs have promising applications in devices.