Enhanced tunability of two-dimensional electron gas on SrTiO3 through heterostructuring

Hyang Keun Yoo; Luca Moreschini; Aaron Bostwick; Andrew L. Walter; Tae Won Noh; Eli Rotenberg; Young Jun Chang

doi:10.1016/j.cap.2020.08.019

Enhanced tunability of two-dimensional electron gas on SrTiO₃ through heterostructuring

Hyang Keun Yoo, Luca Moreschini, Aaron Bostwick, Andrew L. Walter, Tae Won Noh, Eli Rotenberg, Young Jun Chang

Department of Physics

Research output: Contribution to journal › Article › peer-review

4 Scopus citations

Abstract

Two-dimensional electron gases (2DEGs) on the SrTiO₃ (STO) surface or in STO-based heterostructures have exhibited many intriguing phenomena, which are strongly dependent on the 2DEG-carrier density. We report that the tunability of the 2DEG-carrier density is significantly enhanced by adding a monolayer LaTiO₃ (LTO) onto the STO. Ultraviolet (UV) irradiation induced maximum carrier density of the 2DEG in LTO/STO is increased by a factor of ~4 times, compared to that of the bare STO. By oxygen gas exposure, it becomes 10 times smaller than that of the bare STO. This enhanced tunability is attributed to the drastic surface property change of a polar LTO layer by UV irradiation and O₂ exposure. This indicates that the 2DEG controllability in LTO/STO is more reliable than that on the bare STO driven by defects, such an oxygen vacancy.

Original language	English
Pages (from-to)	1268-1273
Number of pages	6
Journal	Current Applied Physics
Volume	20
Issue number	11
DOIs	https://doi.org/10.1016/j.cap.2020.08.019
State	Published - Nov 2020

Keywords

Polar oxide interface
SrTiO
Two-dimensional electron gas
Ultraviolet patterning

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title = "Enhanced tunability of two-dimensional electron gas on SrTiO3 through heterostructuring",

abstract = "Two-dimensional electron gases (2DEGs) on the SrTiO3 (STO) surface or in STO-based heterostructures have exhibited many intriguing phenomena, which are strongly dependent on the 2DEG-carrier density. We report that the tunability of the 2DEG-carrier density is significantly enhanced by adding a monolayer LaTiO3 (LTO) onto the STO. Ultraviolet (UV) irradiation induced maximum carrier density of the 2DEG in LTO/STO is increased by a factor of ~4 times, compared to that of the bare STO. By oxygen gas exposure, it becomes 10 times smaller than that of the bare STO. This enhanced tunability is attributed to the drastic surface property change of a polar LTO layer by UV irradiation and O2 exposure. This indicates that the 2DEG controllability in LTO/STO is more reliable than that on the bare STO driven by defects, such an oxygen vacancy.",

keywords = "Polar oxide interface, SrTiO, Two-dimensional electron gas, Ultraviolet patterning",

author = "Yoo, {Hyang Keun} and Luca Moreschini and Aaron Bostwick and Walter, {Andrew L.} and Noh, {Tae Won} and Eli Rotenberg and Chang, {Young Jun}",

note = "Publisher Copyright: {\textcopyright} 2020 Korean Physical Society",

year = "2020",

month = nov,

doi = "10.1016/j.cap.2020.08.019",

language = "English",

volume = "20",

pages = "1268--1273",

journal = "Current Applied Physics",

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TY - JOUR

T1 - Enhanced tunability of two-dimensional electron gas on SrTiO3 through heterostructuring

AU - Yoo, Hyang Keun

AU - Moreschini, Luca

AU - Bostwick, Aaron

AU - Walter, Andrew L.

AU - Noh, Tae Won

AU - Rotenberg, Eli

AU - Chang, Young Jun

PY - 2020/11

Y1 - 2020/11

N2 - Two-dimensional electron gases (2DEGs) on the SrTiO3 (STO) surface or in STO-based heterostructures have exhibited many intriguing phenomena, which are strongly dependent on the 2DEG-carrier density. We report that the tunability of the 2DEG-carrier density is significantly enhanced by adding a monolayer LaTiO3 (LTO) onto the STO. Ultraviolet (UV) irradiation induced maximum carrier density of the 2DEG in LTO/STO is increased by a factor of ~4 times, compared to that of the bare STO. By oxygen gas exposure, it becomes 10 times smaller than that of the bare STO. This enhanced tunability is attributed to the drastic surface property change of a polar LTO layer by UV irradiation and O2 exposure. This indicates that the 2DEG controllability in LTO/STO is more reliable than that on the bare STO driven by defects, such an oxygen vacancy.

AB - Two-dimensional electron gases (2DEGs) on the SrTiO3 (STO) surface or in STO-based heterostructures have exhibited many intriguing phenomena, which are strongly dependent on the 2DEG-carrier density. We report that the tunability of the 2DEG-carrier density is significantly enhanced by adding a monolayer LaTiO3 (LTO) onto the STO. Ultraviolet (UV) irradiation induced maximum carrier density of the 2DEG in LTO/STO is increased by a factor of ~4 times, compared to that of the bare STO. By oxygen gas exposure, it becomes 10 times smaller than that of the bare STO. This enhanced tunability is attributed to the drastic surface property change of a polar LTO layer by UV irradiation and O2 exposure. This indicates that the 2DEG controllability in LTO/STO is more reliable than that on the bare STO driven by defects, such an oxygen vacancy.

KW - Polar oxide interface

KW - SrTiO

KW - Two-dimensional electron gas

KW - Ultraviolet patterning

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U2 - 10.1016/j.cap.2020.08.019

DO - 10.1016/j.cap.2020.08.019

M3 - Article

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SN - 1567-1739

VL - 20

SP - 1268

EP - 1273

JO - Current Applied Physics

JF - Current Applied Physics

IS - 11

ER -

Enhanced tunability of two-dimensional electron gas on SrTiO₃ through heterostructuring

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Keywords

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