Effect of Point Defects on Electronic Structure of Monolayer GeS

Using density functional theory calculations, atomic and electronic structure of defects in monolayer GeS were investigated by focusing on the effects of vacancies and substitutional atoms. We chose group IV or chalcogen elements as substitutional ones, which substitute for Ge or S in GeS. It was fo...

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Autores principales:	Hyeong-Kyu Choi, Janghwan Cha, Chang-Gyu Choi, Junghwan Kim, Suklyun Hong
Formato:	article
Lenguaje:	EN
Publicado:	MDPI AG 2021
Materias:	germanium monosulfide (GeS) defect formation energy vacancy healing electronic structure piezoelectric coefficients Chemistry QD1-999
Acceso en línea:	https://doaj.org/article/42b28eae3d894cc289f3b8e299f89ab8
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id	oai:doaj.org-article:42b28eae3d894cc289f3b8e299f89ab8
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spelling	oai:doaj.org-article:42b28eae3d894cc289f3b8e299f89ab82021-11-25T18:31:12ZEffect of Point Defects on Electronic Structure of Monolayer GeS10.3390/nano111129602079-4991https://doaj.org/article/42b28eae3d894cc289f3b8e299f89ab82021-11-01T00:00:00Zhttps://www.mdpi.com/2079-4991/11/11/2960https://doaj.org/toc/2079-4991Using density functional theory calculations, atomic and electronic structure of defects in monolayer GeS were investigated by focusing on the effects of vacancies and substitutional atoms. We chose group IV or chalcogen elements as substitutional ones, which substitute for Ge or S in GeS. It was found that the bandgap of GeS with substitutional atoms is close to that of pristine GeS, while the bandgap of GeS with Ge or S vacancies was smaller than that of pristine GeS. In terms of formation energy, monolayer GeS with Ge vacancies is more stable than that with S vacancies, and notably GeS with Ge substituted with Sn is most favorable within the range of chemical potential considered. Defects affect the piezoelectric properties depending on vacancies or substitutional atoms. Especially, GeS with substitutional atoms has almost the same piezoelectric stress coefficients <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mi>e</mi><mrow><mi>i</mi><mi>j</mi></mrow></msub></mrow></semantics></math></inline-formula> as pristine GeS while having lower piezoelectric strain coefficients <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mi>d</mi><mrow><mi>i</mi><mi>j</mi></mrow></msub><mo> </mo></mrow></semantics></math></inline-formula> but still much higher than other 2D materials. It is therefore concluded that Sn can effectively heal Ge vacancy in GeS, keeping high piezoelectric strain coefficients.Hyeong-Kyu ChoiJanghwan ChaChang-Gyu ChoiJunghwan KimSuklyun HongMDPI AGarticlegermanium monosulfide (GeS)defectformation energyvacancy healingelectronic structurepiezoelectric coefficientsChemistryQD1-999ENNanomaterials, Vol 11, Iss 2960, p 2960 (2021)
institution	DOAJ
collection	DOAJ
language	EN
topic	germanium monosulfide (GeS) defect formation energy vacancy healing electronic structure piezoelectric coefficients Chemistry QD1-999
spellingShingle	germanium monosulfide (GeS) defect formation energy vacancy healing electronic structure piezoelectric coefficients Chemistry QD1-999 Hyeong-Kyu Choi Janghwan Cha Chang-Gyu Choi Junghwan Kim Suklyun Hong Effect of Point Defects on Electronic Structure of Monolayer GeS
description	Using density functional theory calculations, atomic and electronic structure of defects in monolayer GeS were investigated by focusing on the effects of vacancies and substitutional atoms. We chose group IV or chalcogen elements as substitutional ones, which substitute for Ge or S in GeS. It was found that the bandgap of GeS with substitutional atoms is close to that of pristine GeS, while the bandgap of GeS with Ge or S vacancies was smaller than that of pristine GeS. In terms of formation energy, monolayer GeS with Ge vacancies is more stable than that with S vacancies, and notably GeS with Ge substituted with Sn is most favorable within the range of chemical potential considered. Defects affect the piezoelectric properties depending on vacancies or substitutional atoms. Especially, GeS with substitutional atoms has almost the same piezoelectric stress coefficients <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mi>e</mi><mrow><mi>i</mi><mi>j</mi></mrow></msub></mrow></semantics></math></inline-formula> as pristine GeS while having lower piezoelectric strain coefficients <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mi>d</mi><mrow><mi>i</mi><mi>j</mi></mrow></msub><mo> </mo></mrow></semantics></math></inline-formula> but still much higher than other 2D materials. It is therefore concluded that Sn can effectively heal Ge vacancy in GeS, keeping high piezoelectric strain coefficients.
format	article
author	Hyeong-Kyu Choi Janghwan Cha Chang-Gyu Choi Junghwan Kim Suklyun Hong
author_facet	Hyeong-Kyu Choi Janghwan Cha Chang-Gyu Choi Junghwan Kim Suklyun Hong
author_sort	Hyeong-Kyu Choi
title	Effect of Point Defects on Electronic Structure of Monolayer GeS
title_short	Effect of Point Defects on Electronic Structure of Monolayer GeS
title_full	Effect of Point Defects on Electronic Structure of Monolayer GeS
title_fullStr	Effect of Point Defects on Electronic Structure of Monolayer GeS
title_full_unstemmed	Effect of Point Defects on Electronic Structure of Monolayer GeS
title_sort	effect of point defects on electronic structure of monolayer ges
publisher	MDPI AG
publishDate	2021
url	https://doaj.org/article/42b28eae3d894cc289f3b8e299f89ab8
work_keys_str_mv	AT hyeongkyuchoi effectofpointdefectsonelectronicstructureofmonolayerges AT janghwancha effectofpointdefectsonelectronicstructureofmonolayerges AT changgyuchoi effectofpointdefectsonelectronicstructureofmonolayerges AT junghwankim effectofpointdefectsonelectronicstructureofmonolayerges AT suklyunhong effectofpointdefectsonelectronicstructureofmonolayerges
_version_	1718411010278162432

Effect of Point Defects on Electronic Structure of Monolayer GeS

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