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Title:Chemical (in)stability of an interface between metals and Bi[sub]2Se[sub]3 topological insulator
Authors:Ferfolja, Katja (Author)
Fanetti, Mattia (Author)
Gardonio, Sandra (Author)
Valant, Matjaž (Author)
Files:URL https://elsevier.conference-services.net/secureProgramme.asp?conferenceID=4266&uID=862277
 
Language:English
Work type:Unknown ()
Tipology:1.12 - Published Scientific Conference Contribution Abstract
Organization:UNG - University of Nova Gorica
Abstract:Our research is dedicated to a study of an interface between a Bi2Se3 topological insulator (TI) and various metals due to the essential need for providing a metal contact for devices. The main objective is to characterize structural and chemical properties at the interface, where the electronic properties of the TI can be affected. The structure of the interface and processes happening at it are investigated by microscopy (SEM, TEM, STM) and spectroscopy techniques (EDX, XPS). The research started with the noble metals: Ag, Au and Pt. A good stability was observed for Au and Pt, whereas Ag reacted with Bi2Se3 already at room temperature, producing Ag2Se and AgBiSe2 phase. Interface stability was also checked at high temperature and results showed that the Au coating undergoes a coalescence process starting from 100 °C whereas the interface with Pt does not show any change at least up to 350 °C. At present we are focused on the interface with Ti, a metal which is regularly used as an adhesive layer in electrical contacts. At low coverage (<30 nm) Ti forms an extremely flat film, smoother than Au, Ag or Pt. At higher coverage the film undergoes buckle delamination, likely induced by stress release. The observed morphology indicates that a chemical interaction leads to the growth of the initial smooth Ti epitaxial film. Se interdiffusion and formation of interfacial TixSey phase is envisaged, as suggested from preliminary TEM observations of the interface structure. The presented results show the importance of the processes happening at the interface, especially solid-state chemical reactions, which are often neglected in the study of systems with metal/TI interfaces. Such instability has to be taken into account since the produced phases can affect transport properties of the material, increase a contact resistance or affect functionality of devices.
Keywords:Bi2Se3, interface, topological insulator, chemical instability
Year of publishing:2019
Number of pages:1 str.
COBISS_ID:73571843 Link is opened in a new window
UDC:54
URN:URN:SI:UNG:REP:YLO6CYJM
Views:236
Downloads:1
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Record is a part of a monograph

Title:3rd International Conference on Applied Surface Science Conference information, 17-20 June 2019, Pisa, Italy
Publisher:s. n.
COBISS.SI-ID:6675482 New window
Place of publishing:Pisa
Year of publishing:2019

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