Metal organic semiconducting structures for electronic band engineering and optoelectronic uses

Semiconducting metal-organic frameworks (MOFs) are hybrid materials, combining the structural flexibility of porous frameworks with the electronic activity of their building blocks, which offer immense opportunities for optoelectronic applications by tuning charge transport and band structures. In this review, we illustrate the principles of electronic band engineering in semiconducting MOFs and the ways in which the choice of metal nodes, conjugated organic linkers, the framework topology, and mixed valence systems, as well as donor-acceptor design and postsynthetic modification, can be used to control the bandgap and charge mobility. The recent developments in thin film architectures, 2D conductive frameworks, and hybrid heterostructures are reviewed. Current problems in electrical conductivity, structural stability, and the challenges of scalable device fabrication are also discussed. Here, we relate the structure design to electronic performance to give a guideline for designing next-generation semiconducting metal-organic frameworks for optoelectronic technologies.