Consequences and Characterization of Device as Interface

Herbert Kroemer stated in his Nobel lecture in 2000 that, “The interface is the device.” This was—at the time—a figurative statement. It is now reality. Two-dimensional materials are interfaces. They are also being seriously considered as the active layer in the logic chips central to modern life by not just academic laboratories but major semiconductor manufacturers. This necessitates identifying both the places that interfacial phenomena will dominate device performance and developing the methods for their measurement. Here, in response, thermal interface phenomena are examined and shown to dominate the self-heating of two-dimensional transition metal dichalcogenide (TMD) transistors due to the inherent softness of the out of plane van Der Waals bonds. Building from simulations of self-heating, in operando measurements of temperature, strain, and photocurrent in 2D-transistors are then implemented to assess the electrical and thermal performance of these interfaces. The combined electro-optical spectroscopic imaging platform is used to identify materials and mechanisms by which the interfaces can be simultaneously co-designed for both electrical and thermal performance.