Detailed Information on Publication Record
2017
Infrared ellipsometry study of photogenerated charge carriers at the (001) and (110) surfaces of SrTiO3 crystals and at the interface of the corresponding LaAlO3/SrTiO3 heterostructures
YAZDI-RIZI, M., Přemysl MARŠÍK, B.P.P. MALLETT, K. SEN, A. CERRETA et. al.Basic information
Original name
Infrared ellipsometry study of photogenerated charge carriers at the (001) and (110) surfaces of SrTiO3 crystals and at the interface of the corresponding LaAlO3/SrTiO3 heterostructures
Authors
YAZDI-RIZI, M. (364 Islamic Republic of Iran), Přemysl MARŠÍK (203 Czech Republic), B.P.P. MALLETT (554 New Zealand), K. SEN (756 Switzerland), A. CERRETA (756 Switzerland), Adam DUBROKA (203 Czech Republic, guarantor, belonging to the institution), M. SCIGAJ (724 Spain), F. SANCHEZ (724 Spain), G. HERRANZ (724 Spain) and Christian BERNHARD (756 Switzerland)
Edition
Physical Review B, MD, USA, AMER PHYSICAL SOC, 2017, 2469-9950
Other information
Language
English
Type of outcome
Článek v odborném periodiku
Field of Study
10302 Condensed matter physics
Country of publisher
United States of America
Confidentiality degree
není předmětem státního či obchodního tajemství
Impact factor
Impact factor: 3.813
RIV identification code
RIV/00216224:14310/17:00100226
Organization unit
Faculty of Science
UT WoS
000400664500004
Keywords in English
infrared ellipsometry; photogenerated charge carriers; LaAlO3; SrTiO3
Tags
International impact, Reviewed
Změněno: 5/4/2018 14:20, Ing. Nicole Zrilić
Abstract
V originále
With infrared (IR) ellipsometry and dc resistance measurements, we investigated the photodoping at the (001) and (110) surfaces of SrTiO3 (STO) single crystals and at the corresponding interfaces of LaAlO3/SrTiO3 (LAO/STO) heterostructures. In the bare STO crystals, we find that the photogenerated charge carriers, which accumulate near the (001) surface, have a similar depth profile and sheet carrier concentration as the confined electrons that were previously observed in LAO/STO (001) heterostructures. A large fraction of these photogenerated charge carriers persist at low temperature at the STO (001) surface even after the ultraviolet light has been switched off again. These persistent charge carriers seem to originate from oxygen vacancies that are trapped at the structural domain boundaries, which develop below the so-called antiferrodistortive transition at T * = 105 K. This is most evident from a corresponding photodoping study of the dc transport in STO (110) crystals for which the concentration of these domain boundaries can be modified by applying a weak uniaxial stress. The oxygen vacancies and their trapping by defects are also the source of the electrons that are confined to the interface of LAO/STO (110) heterostructures, which likely do not have a polar discontinuity as in LAO/STO (001). In the former, the trapping and clustering of the oxygen vacancies also has a strong influence on the anisotropy of the charge carrier mobility. We show that this anisotropy can be readily varied and even inverted by various means, such as a gentle thermal treatment, UV irradiation, or even a weak uniaxial stress. Our experiments suggest that extended defects, which develop over long time periods (of weeks to months), can strongly influence the response of the confined charge carriers at the LAO/STO (110) interface.
Links
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