Role of hydrogen in the n-type oxide semiconductor MgIn2O4: Experimental observation of electrical conductivity and first-principles insight

Hydrogen impurities significantly influence the electrical conductivity of oxide semiconductors such as MgIn2O4, widely used in devices such as thin-film transistors. However, their role and chemical environment have not been fully clarified. This study investigated the conductivity of MgIn2O4 at el...

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Main Authors: Saki Kudo, Tomoyuki Yamasaki, Issei Suzuki, Arunkumar Dorai, Rafael Costa-Amaral, Soungmin Bae, Yu Kumagai, Hiroshi Tanimura, Tetsu Ichitsubo, Takahisa Omata
Format: Article
Language:English
Published: AIP Publishing LLC 2025-04-01
Series:APL Materials
Online Access:http://dx.doi.org/10.1063/5.0253161
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author Saki Kudo
Tomoyuki Yamasaki
Issei Suzuki
Arunkumar Dorai
Rafael Costa-Amaral
Soungmin Bae
Yu Kumagai
Hiroshi Tanimura
Tetsu Ichitsubo
Takahisa Omata
author_facet Saki Kudo
Tomoyuki Yamasaki
Issei Suzuki
Arunkumar Dorai
Rafael Costa-Amaral
Soungmin Bae
Yu Kumagai
Hiroshi Tanimura
Tetsu Ichitsubo
Takahisa Omata
author_sort Saki Kudo
collection DOAJ
description Hydrogen impurities significantly influence the electrical conductivity of oxide semiconductors such as MgIn2O4, widely used in devices such as thin-film transistors. However, their role and chemical environment have not been fully clarified. This study investigated the conductivity of MgIn2O4 at elevated temperatures under air and H2 atmospheres, revealing higher and reversible conductivity in H2 due to hydrogen dissolution. Hall measurements, thermal desorption spectrometry, and nuclear magnetic resonance spectroscopy revealed that hydrogen dissolves in MgIn2O4, ionizing to produce electrons and interstitial protons. Density functional theory calculations indicate that hydrogen stabilizes near vacant octahedral cation sites, forming O–H bonds and shallow donor levels. Indium atoms at magnesium sites lead to shallow donor levels, whereas oxygen vacancies form deep levels. The results identify interstitial hydrogen and indium atoms at magnesium sites, rather than oxygen vacancies, as key donors under H2-rich or low oxygen conditions, providing insights for controlling the conductivity of MgIn2O4 in devices.
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id doaj-art-37b7e9abe31e40708caf647e7381d8a2
institution OA Journals
issn 2166-532X
language English
publishDate 2025-04-01
publisher AIP Publishing LLC
record_format Article
series APL Materials
spelling doaj-art-37b7e9abe31e40708caf647e7381d8a22025-08-20T01:48:13ZengAIP Publishing LLCAPL Materials2166-532X2025-04-01134041118041118-910.1063/5.0253161Role of hydrogen in the n-type oxide semiconductor MgIn2O4: Experimental observation of electrical conductivity and first-principles insightSaki Kudo0Tomoyuki Yamasaki1Issei Suzuki2Arunkumar Dorai3Rafael Costa-Amaral4Soungmin Bae5Yu Kumagai6Hiroshi Tanimura7Tetsu Ichitsubo8Takahisa Omata9Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai, JapanInstitute of Multidisciplinary Research for Advanced Materials, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai, JapanInstitute of Multidisciplinary Research for Advanced Materials, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai, JapanInstitute of Multidisciplinary Research for Advanced Materials, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai, JapanInstitute for Materials Research, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai, JapanInstitute for Materials Research, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai, JapanInstitute for Materials Research, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai, JapanInstitute for Materials Research, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai, JapanInstitute for Materials Research, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai, JapanInstitute of Multidisciplinary Research for Advanced Materials, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai, JapanHydrogen impurities significantly influence the electrical conductivity of oxide semiconductors such as MgIn2O4, widely used in devices such as thin-film transistors. However, their role and chemical environment have not been fully clarified. This study investigated the conductivity of MgIn2O4 at elevated temperatures under air and H2 atmospheres, revealing higher and reversible conductivity in H2 due to hydrogen dissolution. Hall measurements, thermal desorption spectrometry, and nuclear magnetic resonance spectroscopy revealed that hydrogen dissolves in MgIn2O4, ionizing to produce electrons and interstitial protons. Density functional theory calculations indicate that hydrogen stabilizes near vacant octahedral cation sites, forming O–H bonds and shallow donor levels. Indium atoms at magnesium sites lead to shallow donor levels, whereas oxygen vacancies form deep levels. The results identify interstitial hydrogen and indium atoms at magnesium sites, rather than oxygen vacancies, as key donors under H2-rich or low oxygen conditions, providing insights for controlling the conductivity of MgIn2O4 in devices.http://dx.doi.org/10.1063/5.0253161
spellingShingle Saki Kudo
Tomoyuki Yamasaki
Issei Suzuki
Arunkumar Dorai
Rafael Costa-Amaral
Soungmin Bae
Yu Kumagai
Hiroshi Tanimura
Tetsu Ichitsubo
Takahisa Omata
Role of hydrogen in the n-type oxide semiconductor MgIn2O4: Experimental observation of electrical conductivity and first-principles insight
APL Materials
title Role of hydrogen in the n-type oxide semiconductor MgIn2O4: Experimental observation of electrical conductivity and first-principles insight
title_full Role of hydrogen in the n-type oxide semiconductor MgIn2O4: Experimental observation of electrical conductivity and first-principles insight
title_fullStr Role of hydrogen in the n-type oxide semiconductor MgIn2O4: Experimental observation of electrical conductivity and first-principles insight
title_full_unstemmed Role of hydrogen in the n-type oxide semiconductor MgIn2O4: Experimental observation of electrical conductivity and first-principles insight
title_short Role of hydrogen in the n-type oxide semiconductor MgIn2O4: Experimental observation of electrical conductivity and first-principles insight
title_sort role of hydrogen in the n type oxide semiconductor mgin2o4 experimental observation of electrical conductivity and first principles insight
url http://dx.doi.org/10.1063/5.0253161
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