Show simple item record

dc.contributor.advisorJahangirov, Seymur
dc.contributor.authorErshadrad, Soheil
dc.date.accessioned2021-09-16T07:23:39Z
dc.date.available2021-09-16T07:23:39Z
dc.date.copyright2021-08
dc.date.issued2021-08
dc.date.submitted2021-09-15
dc.identifier.urihttp://hdl.handle.net/11693/76518
dc.descriptionCataloged from PDF version of article.en_US
dc.descriptionThesis (Master's): Bilkent University, Department of Materials Science and Nanotechnology, İhsan Doğramacı Bilkent University, 2021.en_US
dc.descriptionIncludes bibliographical references (leaves 54-61).en_US
dc.description.abstractTetrahex materials are a novel family of 2D materials, made of an ordered se-quence of tetragons and hexagons, with exotic electronic, optical and mechanical properties. Motivated by the promising photocatalytic and auxetic properties found in the Tetrahex-carbon, we investigate the behavior of binary group IV-V polymorphs in this structure (denoted by th-XY2 where X = C and Si, and Y = N, P, As, and Sb), through first-principles methods. We demonstrate that these compounds exhibit robust energetic, dynamical, thermal, and mechanical stabilities. Our calculations show that the intrinsic structural anisotropy within this family induces strongly anisotropic mechanical, electronic, and optical behav-ior. These materials offer high ultimate strain, comparable to that of graphene. The majority are semiconductors in nature, where th-CAs2 and th-CP2 possess direct and quasi-direct band gaps, respectively, and the rest have indirect band gaps. Besides, an indirect-to-direct band gap transition can be induced in th-CSb2 through strain engineering. Studied compounds have good optical absorption in the visible and ultraviolet regions of the light spectrum, suitable for optoelectron-ics applications. Their band gaps are wide enough to provide the photogenerated energy required for the splitting of water. In th-CAs2 and th-CP2, the positions of band edges are perfectly compatible with the water oxidation and reduction potentials. Besides, they offer anisotropic high charge carrier mobilities, which prolongs the average lifetime of charge carrier drift. Having all these features in one package, these compounds, especially th-CAs2 and th-CP2, can be consid-ered promising candidates for high-performance photocatalytic water splitting. Moreover, we found auxetic behavior in th-CN2 and th-SiN2 around their equilib-rium structure. Having this rare feature endows these compounds with potential applicability in numerous areas, from biotechnology to defense.en_US
dc.description.statementofresponsibilityby Soheil Ershadraden_US
dc.format.extentxvi, 67 leaves : charts (some color) ; 30 cm.en_US
dc.language.isoEnglishen_US
dc.rightsinfo:eu-repo/semantics/openAccessen_US
dc.subjectDensity functional theoryen_US
dc.subject2D Semiconductoren_US
dc.subjectPhotocatalysten_US
dc.subjectAuxeticen_US
dc.titleFirst-principles study of binary group IV-V polymorphs in 2D tetrahex structureen_US
dc.title.alternativeTetrahex yapısındaki grup IV-V ikili polimorflarn ilk ilkeler yöntemi ile incelenmesien_US
dc.typeThesisen_US
dc.departmentInstitute of Materials Science and Nanotechnology (UNAM)en_US
dc.publisherBilkent Universityen_US
dc.description.degreeM.S.en_US
dc.identifier.itemidB153691
dc.embargo.release2022-02-15


Files in this item

Thumbnail

This item appears in the following Collection(s)

Show simple item record