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Surface Reconstruction, Oxidation Mechanism, and Stability of Cd 3 As 2
Author(s) -
Gao Junfeng,
Cupolillo Anna,
Nappini Silvia,
Bondino Federica,
Edla Raju,
Fabio Vito,
Sankar Raman,
Zhang YongWei,
Chiarello Gennaro,
Politano Antonio
Publication year - 2019
Publication title -
advanced functional materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 6.069
H-Index - 322
eISSN - 1616-3028
pISSN - 1616-301X
DOI - 10.1002/adfm.201900965
Subject(s) - dangling bond , materials science , scanning tunneling microscope , surface reconstruction , chemical physics , ab initio , crystallography , ab initio quantum chemistry methods , surface (topology) , nanotechnology , molecule , silicon , optoelectronics , chemistry , geometry , mathematics , organic chemistry
Abstract Cadmium arsenide (Cd 3 As 2 ) has recently attracted considerable interest for the presence of 3D massless Dirac fermions with ultrahigh mobility and magnetoresistance. However, its surface properties are currently largely unexplored both theoretically and experimentally, due to the very large unit cell and the challenging growth of single‐crystal samples, respectively. Here, by combining ab initio calculations with surface‐science spectroscopic experiments, the presence of a surface reconstruction is unveiled in centimeter‐scale (112)‐oriented Cd 3 As 2 single‐crystal foils produced by the self‐selecting vapor growth. Outermost Cd atoms descend into the As‐sublayer with a subsequent self‐passivation of the dangling bonds with As atoms, forming the triangle lattice previously imaged by scanning tunneling microscopy. Moreover, the oxidation mechanism of this reconstructed surface, dominated by the formation of AsOCd bonds, is revealed. Interestingly, it is found that the band structure of the reconstructed surface of Cd 3 As 2 is quite robust against surface oxidation. Both computational and experimental findings point to a successful exploitation in technology of Cd 3 As 2 single crystals.