Direct Nanoscale Characterization of Deep Levels in AgCuInGaSe2 Using Electron Energy-Loss Spectroscopy in the Scanning Transmission Electron Microscope - Deitz, J; Paul, PK; Farshchi, R; Poplavskyy, D; Bailey, J; Arehart, AR; McComb, DW; Grassman, TJ (ADVANCED ENERGY MATERIALS, 2019)