High-Performance Single Layered WSe<sub>2</sub> p-FETs with Chemically Doped ContactsWe report high performance p-type field-effect transistors based on single layered (thickness, ∼0.7 nm) WSe(2) as the active channel with chemically doped source/drain contacts and high-κ gate dielectrics. The top-gated monolayer transistors exhibit a high effective hole mobility of ∼250 cm(2)/(V s), perfect subthreshold swing of ∼60 mV/dec, and I(ON)/I(OFF) of >10(6) at room temperature. Special attention is given to lowering the contact resistance for hole injection by using high work function Pd contacts along with degenerate surface doping of the contacts by patterned NO(2) chemisorption on WSe(2). The results here present a promising material system and device architecture for p-type monolayer transistors with excellent characteristics.
Fully Printed, High Performance Carbon Nanotube Thin-Film Transistors on Flexible SubstratesFully printed transistors are a key component of ubiquitous flexible electronics. In this work, the advantages of an inverse gravure printing technique and the solution processing of semiconductor-enriched single-walled carbon nanotubes (SWNTs) are combined to fabricate fully printed thin-film transistors on mechanically flexible substrates. The fully printed transistors are configured in a top-gate device geometry and utilize silver metal electrodes and an inorganic/organic high-κ (~17) gate dielectric. The devices exhibit excellent performance for a fully printed process, with mobility and on/off current ratio of up to ~9 cm(2)/(V s) and 10(5), respectively. Extreme bendability is observed, without measurable change in the electrical performance down to a small radius of curvature of 1 mm. Given the high performance of the transistors, our high-throughput printing process serves as an enabling nanomanufacturing scheme for a wide range of large-area electronic applications based on carbon nanotube networks.
Toward the Development of Printable Nanowire Electronics and SensorsAbstract In recent years, there has been tremendous progress in the research and development of printable electronics on mechanically flexible substrates based on inorganic active components, which provide high performances and stable device operations at low cost. In this regard, various approaches have been developed for the direct transfer or printing of micro‐ and nanoscale, inorganic semiconductors on substrates. In this review article, we focus on the recent advancements in the large‐scale integration of single crystalline, inorganic‐nanowire (NW) arrays for electronic and sensor applications, specifically involving the contact printing of NWs at defined locations. We discuss the advantages, limitations, and the state‐of‐the‐art of this technology, and present an integration platform for future printable, heterogeneous‐sensor circuitry based on NW parallel arrays.