Multislice Hollow Ptychography for Simultaneous Atomic-Layer-Resolved 3D Structural Imaging and Spectroscopy

Abstract: Electron matter interactions in electron microscopy produce both elastic and inelastic scattering, forming the basis for imaging and spectroscopy. However, the integration of electron energy loss spectroscopy (EELS) with 4D-STEM and electron ptychography remains challenging because of detector geometry conflicts. Song et al. solved this issue by introducing a hollow type pixelated detector that enables hollow ptychography and allows low angle electrons to go through to the EELS spectrometer. The single-slice approach of hollow ptychography proves effective for 2D thin materials but struggles with multiple scattering in thicker specimens. Here, we introduce multislice hollow ptychography (MHP), a robust imaging modality that overcomes these limitations by accounting for multiple scattering. MHP enables high-resolution structural imaging from hollow diffraction patterns while remaining compatible with simultaneous EELS acquisition. It potentially can provide sub-angstrom lateral resolution at intermediate doses and supports full 3D atomic-layer reconstruction at ultrahigh doses, with up to 70% of total electrons available for spectroscopy. This flexible framework facilitates correlative 3D imaging and chemical mapping in complex materials, including interfaces, defects, and dopants.