Nanoimprint-assisted shear exfoliation plus transfer printing for producing transition metal dichalcogenide heterostructures

The authors present a nanofabrication technology capable of producing arrays of transition metal dichalcogenide heterostructures that are needed for a broad range of nanoelectronic and optoelectronic device applications. This nanofabrication approach uniquely combines nanoimprint-assisted shear exfoliation (NASE) and transfer printing (TP). Using this NASE + TP method, the authors have demonstrated production of WSe2/MoS2 heterostructure arrays with a high uniformity in feature thicknesses (relative standard deviation <12%). The authors have also created photodiode devices based on such WSe2/MoS2 heterostructures, which exhibit significantly enhanced degrees of current rectification as well as photovoltaic responses in comparison with pure WSe2 devices. Such results indicate that a sizable built-in potential is formed at the pristine WSe2/MoS2 interface. This work advances the top-down approaches for manufacturing high-quality functional heterostructures based on emerging layered semiconductors.