A programmable dark-field detector for imaging two-dimensional materials in the scanning electron microscope

Unit cell orientation information is encoded in electron diffraction patterns of crystalline materials. Traditional transmission electron detectors implemented in the scanning electron microscope are highly symmetric and are insensitive to in-plane unit cell orientation information. Herein we detail the implementation of a transmission electron detector that utilizes a digital micromirror array to select anisotropic portions of a diffraction pattern for imaging purposes. We demonstrate that this detector can be used to map the in-plane orientation of grains in two-dimensional materials. The described detector has the potential to replace and/or supplement conventional transmission electron detectors.