(Invited) Improving Conducting and Insulating Interfaces to 2D Materials

Abstract

Bulk semiconductors remain the backbone of the ongoing technological revolution and continue to enhance the computational ability and accessibility of data. However, as the range of possible applications for electronics grows, so does the realization that there are distinct limits to what bulk materials can do. 2D layered materials, including graphene and transition metal dichalcogenides (TMDs), present nearly limitless possibilities for new electronic devices. While these materials are very encouraging based on their intrinsic properties, establishing conducting and insulating interfaces (needed to form useful 2D electronic devices) compromises the desirable intrinsic behavior. In this talk, recent advances in establishing scalable, high-performance conducting interfaces to semiconducting 2D materials will be presented. This includes the use of an in situ ion beam source to modify 2D materials during the deposition of contact metals in 2D field-effect transistors. The establishment of pure edge contacts using this approach is able to yield devices with ultimate scalability. In addition to the improvement of conducting interfaces, the ability to nucleate ultrathin insulating materials on the inert surface of various 2D materials will also be discussed. Using plasma-enhanced atomic layer deposition, sub-5 nm films can be realized without hampering the performance of few-layer thick 2D crystals or requiring the inclusion of a buffer layer. In some cases, the electronic properties of the 2D material are preserved and even enhanced at the device-level. Improvement of these critical conducting and insulating interfaces to 2D materials has wide-ranging value for their integration into new electronic and optoelectronic devices.