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X‐Ray Writing of Metallic Conductivity and Oxygen Vacancies at Silicon/SrTiO 3 Interfaces
Author(s) -
Chikina Alla,
Caputo Marco,
Naamneh Muntaser,
Christensen Dennis Valbjørn,
Schmitt Thorsten,
Radovic Milan,
Strocov Vladimir N.
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.201900645
Subject(s) - materials science , amorphous solid , oxygen , oxide , chemical physics , photoemission spectroscopy , silicon , conductivity , metal , x ray photoelectron spectroscopy , condensed matter physics , nanotechnology , optoelectronics , chemical engineering , crystallography , chemistry , physics , organic chemistry , engineering , metallurgy
Tunable electronic properties of transition metal oxides and their interfaces offer remarkable functionalities for future devices. The interest in these materials has been boosted with the discovery of a 2D electron gas (2DEG) at SrTiO 3 (STO)‐based interfaces. For the majority of these systems, oxygen vacancies play a crucial role in the emergence of interface conductivity, ferromagnetism, and high electron mobility. Despite its great importance, controlling the density and spatial distribution of oxygen vacancies in a dynamic way remains extremely challenging. Here, lithography‐like writing of a metallic state at the interface between SrTiO 3 and amorphous Si using X‐ray irradiation is reported. Using a combination of transport techniques and in operando photoemission spectroscopy, it is revealed in real time that the X‐ray radiation induces transfer of oxygen across the interface leading to the on‐demand formation of oxygen vacancies and a 2DEG in STO. The formed 2DEG stays stable in ambient conditions as the interface oxygen vacancies are stabilized by the capping of Si. The study provides a fundamental understanding of X‐ray‐induced redox reactions at the SrTiO 3 ‐based interfaces and in addition shows the potential of X‐ray radiation for patterning stabile conductive pathways for future oxide‐based electronic devices.