Mapping the energy landscape: scanning probe microscopy of 2D devices

Interest in 2D materials systems has exploded in recent years, as researchers have explored new materials and stacked them together in various combinations. Investigations range from manufacturable devices to systems exhibiting exotic physical behavior at low temperatures. A tool that seems convenient and well suited for studying 2D materials and devices is Kelvin probe force microscopy (KPFM), which in principle can map the electric potential variation with position or applied voltages, allowing the device operation to be spatially mapped and identifying features hidden in topographic scans. I will discuss our recent applications of probe microscopy to 2D materials and devices, highlighting both successes and cautionary tales.