Bell

Biscaras

Brinkman

Caviglia

Chen

Cheng

Choi

Christensen

Cordero

Delahaye

Gunkel

Honig

Hwang

Kalabukhov

Lontsi-Fomena

Meyer

Mikheev

Monroe

Murphy

Nabatame

Nakagawa

Ngai

Pavlenko

Rhodes

Shibuya

Thiel

Trier

Verma

Walker

Waser

The conducting interface between the insulating oxides LaAlO3 (LAO) and SrTiO3 (STO) displays numerous physical phenomena that can be tuned by varying the carrier density, which is generally achieved by electrostatic gating or adjustment of growth parameters. Here, it is reported how annealing in oxygen at low temperatures (T &lt; 300 °C) can be used as a simple route to control the carrier density by several orders of magnitude. The pathway to control the carrier density relies on donor oxidation and is thus applicable to material systems where oxygen vacancies are the dominant source of conductivity. Using STO capped with epitaxial γ-Al2O3 (GAO) or amorphous LAO (a-LAO), the pathways for changing the carrier density in the two STO-based cases are identified where oxygen blocking (GAO) and oxygen permeable (a-LAO) films create interface conductivity from oxygen vacancies located in STO near the interface. For a-LAO/STO, the rate limiting step (Ea = 0.25 eV) for oxidizing oxygen vacancies is the transportation of oxygen from the atmosphere through the a-LAO film, whereas GAO/STO is limited by oxygen migration inside STO (Ea = 0.5 eV). Finally, it is showed how the control of the carrier density enables writing of conducting nanostructures in γ-Al2O3/STO by conducting atomic force microscopy

Christensen, Dennis Valbjørn

von Soosten, Merlin

Trier, Felix

Sand Jespersen, Thomas

Smith, Anders

Chen, Yunzhong

Pryds, Nini

Online Research Database In Technology

Controlling the Carrier Density of SrTiO<sub>3</sub>-Based Heterostructures with Annealing

Dennis V. Christensen

Merlin von Soosten

Felix Trier

Thomas S. Jespersen

Anders Smith

Yunzhong Chen

Nini Pryds

Crossref

Advanced Electronic Materials

Controlling the Carrier Density of SrTiO<sub>3</sub>
-Based Heterostructures with Annealing

The conducting interface between the insulating oxides LaAlO3 (LAO) and SrTiO3 (STO) displays numerous physical phenomena that can be tuned by varying the carrier density, which is generally achieved by electrostatic gating or adjustment of growth parameters. Here, it is reported how annealing in oxygen at low temperatures (T &lt; 300 °C) can be used as a simple route to control the carrier density by several orders of magnitude. The pathway to control the carrier density relies on donor oxidation and is thus applicable to material systems where oxygen vacancies are the dominant source of conductivity. Using STO capped with epitaxial γ-Al2O3 (GAO) or amorphous LAO (a-LAO), the pathways for changing the carrier density in the two STO-based cases are identiﬁed where oxygen blocking (GAO) and oxygen permeable (a-LAO) ﬁlms create interface conductivity from oxygen vacan-cies located in STO near the interface. For a-LAO/STO, the rate limiting step (Ea = 0.25 eV) for oxidizing oxygen vacancies is the transportation of oxygen from the atmosphere through the a-LAO ﬁlm, whereas GAO/STO is limited by oxygen migration inside STO (Ea = 0.5 eV). Finally, it is showed how the control of the carrier density enables writing of conducting nanostructures in γ-Al2O3/STO by conducting atomic force microscopy

Christensen, Dennis V.

Jespersen, Thomas S.

Copenhagen University Research Information System

English

http://orbit.dtu.dk/ws/files/150263532/GAO_STO_annealing_vPostprint.pdf

Controlling the Carrier Density of SrTiO<sub>3</sub>-Based Heterostructures with Annealing

Abstract

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Online Research Database In Technology

Crossref

Copenhagen University Research Information System