Tuning band alignment at a semiconductor-crystalline oxide heterojunction via electrostatic modulation of the interfacial dipole

DOI: 10.1103/PhysRevMaterials.5.104603

Authors: M. Chrysler (University of Texas-Arlington) , J. Gabel (Diamond Light Source) , T.-L. Lee (Diamond Light Source) , A. N. Penn (North Carolina State University) , B. E. Matthews (Pacific Northwest National Laboratory) , D. M. Kepaptsoglou (SuperSTEM; University of York) , Q. M. Ramasse (SuperSTEM; University of Leeds) , J. R. Paudel (Temple University) , R. K. Sah (Temple University) , J. D. Grassi (Temple University) , Z. Zhu (Pacific Northwest National Laboratory) , A. X. Gray (Temple University) , J. M. Lebeau (Massachusetts Institute of Technology) , S. R. Spurgeon (Pacific Northwest National Laboratory) , S. A. Chambers (Pacific Northwest National Laboratory) , P. V. Sushko (Pacific Northwest National Laboratory) , J. H. Ngai (University of Texas-Arlington)
Co-authored by industrial partner: No

Type: Journal Paper
Journal: Physical Review Materials , VOL 5

State: Published (Approved)
Published: October 2021
Diamond Proposal Number(s): 25582 , 26487

Abstract: We demonstrate that the interfacial dipole associated with bonding across the SrTi O 3 / Si heterojunction can be tuned through space charge, thereby enabling the band alignment to be altered via doping. Oxygen impurities in Si act as donors that create space charge by transferring electrons across the interface into SrTi O 3 . The space charge induces an electric field that modifies the interfacial dipole, thereby tuning the band alignment from type II to III. The transferred charge, accompanying built-in electric fields, and change in band alignment are manifested in electrical transport and hard x-ray photoelectron spectroscopy measurements. Ab initio models reveal the interplay between polarization and band offsets. We find that band offsets can be tuned by modulating the density of space charge across the interface. Modulating the interface dipole to enable electrostatic altering of band alignment opens additional pathways to realize functional behavior in semiconducting hybrid heterojunctions.

Journal Keywords: Dielectric properties; Electrical conductivity; Hall effect; Microstructure; Interfaces; Density functional theory; Photoemission spectroscopy

Diamond Keywords: Semicoductors

Subject Areas: Materials, Physics


Instruments: I09-Surface and Interface Structural Analysis

Added On: 11/10/2021 11:40

Discipline Tags:

Surfaces Physics Hard condensed matter - structures Materials Science interfaces and thin films

Technical Tags:

Spectroscopy X-ray Photoelectron Spectroscopy (XPS) Hard X-ray Photoelectron Spectroscopy (HAXPES)