Modifying the band gap and optical properties of Germanium nanowires by surface termination

Simple item page
dc.check.date2018-11-15
dc.check.infoAccess to this item is restricted until 24 months after publication by the request of the publisheren
dc.contributor.authorLegesse, Merid
dc.contributor.authorFagas, Gíorgos
dc.contributor.authorNolan, Michael
dc.contributor.funderScience Foundation Irelanden
dc.contributor.funderEuropean Commissionen
dc.contributor.funderSeventh Framework Programmeen
dc.date.accessioned2016-11-22T09:41:25Z
dc.date.available2016-11-22T09:41:25Z
dc.date.issued2016-11-15
dc.description.abstractSemiconductor nanowires, based on silicon (Si) or germanium (Ge) are leading candidates for many ICT applications, including next generation transistors, optoelectronics, gas and biosensing and photovoltaics. Key to these applications is the possibility to tune the band gap by changing the diameter of the nanowire. Ge nanowires of different diameter have been studied with H termination, but, using ideas from chemistry, changing the surface terminating group can be used to modulate the band gap. In this paper we apply the generalised gradient approximation of density functional theory (GGA-DFT) and hybrid DFT to study the effect of diameter and surface termination using –H, –NH2 and –OH groups on the band gap of (001), (110) and (111) oriented germanium nanowires. We show that the surface terminating group allows both the magnitude and the nature of the band gap to be changed. We further show that the absorption edge shifts to longer wavelength with the –NH2 and –OH terminations compared to the –H termination and we trace the origin of this effect to valence band modifications upon modifying the nanowire with –NH2 or –OH. These results show that it is possible to tune the band gap of small diameter Ge nanowires over a range of ca. 1.1 eV by simple surface chemistry.en
dc.description.sponsorshipScience Foundation Ireland (SFI Starting Investigator Research Grant Program, project EMOIN grant number SFI 09/SIRG/I1620)en
dc.description.statusPeer revieweden
dc.description.versionAccepted Versionen
dc.format.mimetypeapplication/pdfen
dc.identifier.citationLegesse, M., Fagas, G. and Nolan, M. (2016) ‘Modifying the band gap and optical properties of Germanium nanowires by surface termination’, Applied Surface Science, 396, pp. 1155-1163. doi: 10.1016/j.apsusc.2016.11.104en
dc.identifier.doi10.1016/j.apsusc.2016.11.104
dc.identifier.endpage1163
dc.identifier.issn0169-4332
dc.identifier.journaltitleApplied Surface Scienceen
dc.identifier.startpage1155
dc.identifier.urihttps://hdl.handle.net/10468/3299
dc.identifier.volume396
dc.language.isoenen
dc.publisherElsevieren
dc.relation.projectinfo:eu-repo/grantAgreement/EC/FP7::SP1::ICT/257856/EU/Semiconducting Nanowire Platform for Autonomous Sensors/SINAPSen
dc.rights© 2016, Elsevier Inc. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/en
dc.rights.urihttp://creativecommons.org/licenses/by-nc-nd/4.0/en
dc.subjectGe-nanowiresen
dc.subjectBandgapen
dc.subjectSurface terminationen
dc.subjectDFTen
dc.subjectAdsoptionen
dc.titleModifying the band gap and optical properties of Germanium nanowires by surface terminationen
dc.typeArticle (peer-reviewed)en
Files
Original bundle
Now showing 1 - 1 of 1
Thumbnail Image
Name:
1811.pdf
Size:
2.11 MB
Format:
Adobe Portable Document Format
Description:
Accepted Version
Download
License bundle
Now showing 1 - 1 of 1
Thumbnail Image
Name:
license.txt
Size:
2.71 KB
Format:
Item-specific license agreed upon to submission
Description:
Download
Collections
Tyndall National Institute - Journal Articles