This title appears in the Scientific Report :
2022
Please use the identifier:
http://dx.doi.org/10.1002/smll.202201753 in citations.
Please use the identifier: http://hdl.handle.net/2128/31259 in citations.
Scaling and Confinement in Ultrathin Chalcogenide Films as Exemplified by GeTe
Scaling and Confinement in Ultrathin Chalcogenide Films as Exemplified by GeTe
Chalcogenides such as GeTe, PbTe, Sb2Te3, and Bi2Se3 are characterized by an unconventional combination of properties enabling a plethora of applications ranging from thermo-electrics to phase change materials, topological insulators, and photonic switches. Chalcogenides possess pronounced optical a...
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Personal Name(s): | Kerres, Peter (Corresponding author) |
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Zhou, Yiming / Vaishnav, Hetal / Raghuwanshi, Mohit / Wang, Jiangjing / Häser, Maria / Pohlmann, Marc / Cheng, Yudong / Schön, Carl-Friedrich / Jansen, Thomas / Bellin, Christophe / Bürgler, Daniel E. / Jalil, Abdur Rehman / Ringkamp, Christoph / Kowalczyk, Hugo / Schneider, Claus M. / Shukla, Abhay / Wuttig, Matthias (Corresponding author) | |
Contributing Institute: |
Halbleiter-Nanoelektronik; PGI-9 Elektronische Eigenschaften; PGI-6 JARA Institut Green IT; PGI-10 |
Published in: | Small, 18 (2022) 21, S. 2201753 - |
Imprint: |
Weinheim
Wiley-VCH
2022
|
DOI: |
10.1002/smll.202201753 |
Document Type: |
Journal Article |
Research Program: |
Memristive Materials and Devices |
Link: |
OpenAccess |
Publikationsportal JuSER |
Please use the identifier: http://hdl.handle.net/2128/31259 in citations.
Chalcogenides such as GeTe, PbTe, Sb2Te3, and Bi2Se3 are characterized by an unconventional combination of properties enabling a plethora of applications ranging from thermo-electrics to phase change materials, topological insulators, and photonic switches. Chalcogenides possess pronounced optical absorption, relatively low effective masses, reasonably high electron mobilities, soft bonds, large bond polarizabilities, and low thermal conductivities. These remarkable characteristics are linked to an unconventional bonding mechanism characterized by a competition between electron delocalization and electron localization. Confinement, that is, the reduction of the sample dimension as realized in thin films should alter this competition and modify chemical bonds and the resulting properties. Here, pronounced changes of optical and vibrational properties are demonstrated for crystalline films of GeTe, while amorphous films of GeTe show no similar thickness dependence. For crystalline films, this thickness dependence persists up to remarkably large thicknesses above 15 nm. X-ray diffraction and accompanying simulations employing density functional theory relate these changes to thickness dependent structural (Peierls) distortions, due to an increased electron localization between adjacent atoms upon reducing the film thickness. A thickness dependence and hence potential to modify film properties for all chalcogenide films with a similar bonding mechanism is expected. |