Simultaneous Atomic Resolution Imaging and Electronic Characterization of Wet-Chemically Prepared Nanocrystals.

Abstract

Wet-chemical colloidal synthesis has emerged as a major platform for producing metallic, magnetic, and semiconducting nanomaterials, which have extensive applications in optoelectronics and hold promise in quantum technology. However, simultaneous characterization of the atomic and electronic structure─correlating the two─has not been possible for these materials due to the detrimental effects of surface ligands and solvent molecules. Using a viscoelastic transfer method, we could deposit isolated, wet-chemically prepared Bi₂Se₃ nanoplatelets onto an atomically clean surface in ultrahigh vacuum, with limited cotransfer of solvent molecules. We image the atomic structure of the surface with scanning tunnelling microscopy and characterize the impact of (sub)surface point defects and adsorbates on the electronic band structure. This work opens the stage to connect the atomic structure to the electronic and optical properties of wet-chemically prepared nanocrystals─a long-standing challenge for one of the major platforms in materials science.