Toward electron exit wave tomography of amorphous materials at atomic resolution

We suggest to use electron exit wave phase for tomographic reconstruction of structure of Au-doped amorphous Si with atomic resolution. In the present theoretical investigation into the approach it is found that the number of projections and the accuracy of defocus in the focal series restoration are the main factors that contribute to the final resolution. Although resolution is ultimately limited by these factors, phase shifts in the exit wave are sufficient to identify the position of Au atoms in an amorphous Si needle model, even when only 19 projections with defocus error of 4 nm are used. Electron beam damage will probably further limit the resolution of such tomographic reconstructions, however beam damage can be mitigated using lower accelerating voltages.

► We suggest a novel electron exit wave tomography approach to obtain three dimensional atomic structures of amorphous materials. ► Theoretical tests using a model of amorphous Si doped with Au show that it is feasible to reconstruct both Si and Au atoms positions. ► Reconstructions of the strongly scattering Au atoms positions appear to be insensitive to typical experimental errors.