2018_JVST_ZnTe_CdTe_Cu_2018.pdf (1.49 MB)
Copper-induced recrystallization and interdiffusion of CdTe/ZnTe thin films
journal contribution
posted on 2018-06-15, 10:43 authored by Yegor Samoilenko, Ali AbbasAli Abbas, Michael WallsMichael Walls, Colin A. Wolden© 2018 Author(s). ZnTe is commonly employed as a buffer layer between CdTe and the metallization layer at the back contact of state-of-the-art CdTe solar cells. Here, the critical role of Cu in catalyzing recrystallization and interdiffusion between CdTe and ZnTe layers during back contact activation is presented. Several CdTe/ZnTe:Cu thin-film samples were prepared with varying levels of copper loading and annealed as a function of temperature and time. The samples were characterized by x-ray diffractometry, scanning electron microscopy, transmission electron microscopy, and energy dispersive x-ray spectroscopy. The results show that stress is present in the as-deposited bilayers and that negligible interdiffusion occurs in the absence of Cu. The presence of Cu facilitates rapid interdiffusion, predominantly via Cd migration into the ZnTe phase. Zn migration into CdTe is limited to areas around defects and grain boundaries. Ternary Cd x Zn 1-x Te interlayers are formed, and the extent of alloy formation ranges from 0.08 < x < 0.5 throughout the whole ZnTe layer. The level of Cu loading controls the composition of the Cu x Te clusters observed, while their size and migration is a function of annealing conditions.
Funding
The CSM authors are grateful to the National Science Foundation through award number CBET-1706149.The Loughborough authors are grateful to UKERC for funding this work through the EPSRC Supergen SuperSolar Hub, grants EP/J017361/1 and EP/M014797/1.
History
School
- Mechanical, Electrical and Manufacturing Engineering
Published in
Journal of Vacuum Science and Technology A: Vacuum, Surfaces and FilmsVolume
36Issue
3Citation
SAMOILENKO, Y. ...et al., 2018. Copper-induced recrystallization and interdiffusion of CdTe/ZnTe thin films. Journal of Vacuum Science and Technology A: Vacuum, Surfaces and Films, 36(3): 031201.Publisher
AIPVersion
- AM (Accepted Manuscript)
Publisher statement
This work is made available according to the conditions of the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0) licence. Full details of this licence are available at: https://creativecommons.org/licenses/by-nc-nd/4.0/Acceptance date
2018-04-30Publication date
2018Notes
This paper was accepted for publication in the journal Journal of Vacuum Science and Technology A: Vacuum, Surfaces and Films and the definitive published version is available at https://doi.org/10.1116/1.5023501.ISSN
0734-2101eISSN
1520-8559Publisher version
Language
- en