PVSC-42 full back contact_final (2).pdf (968.02 kB)
Structural and chemical characterization of the back contact region in high efficiency CdTe solar cells
conference contribution
posted on 2016-03-04, 11:54 authored by Ali AbbasAli Abbas, Daniel M. Meysing, Jiaojiao Li, Joseph D. Beach, Teresa M. Barnes, Colin A. WoldenCadmium telluride (CdTe) is the leading
commercialized thin-film photovoltaic technology. Copper is
commonly used in back contacts to obtain high efficiency, but has
also been implicated as a harmful factor for device stability. T hus
it is critical to understand its composition and distribution within
complete devices. In this work the composition and structure of
the back contact region was examined in high efficiency devices
(-16%) contacted using a ZnTe:Cu buffer layer followed by gold
metallization. T he microstructure was examined in the asdeposited
state and after rapid thermal processing (RTP) using
high resolution transmission electron microscopy and EDX
chemical mapping. After RTP the ZnTe exhibits a bilayer
structure with polycrystalline, twinned grains adjacent to Au and
an amorphous region adjacent to CdTe characterized by extensive
Cd-Zn interdiffusion. T he copper that is co-deposited uniformly
within ZnTe is found to segregate dramatically after RTP
activation, either collecting near the ZnTe/Au interface or forming
CUxTe clusters in CdTe at defects or grain boundaries near the
interface with ZnTe. Chlorine, present throughout CdTe and
concentrated at grain boundaries, does not penetrate significantly
into the back contact region during RTP activation.
Funding
We gratefully acknowledge the Bay Area Photovoltaic Consortium for their support of the work performed at CSM under U.S. Department of Energy Award number DEEE0004946. Work at NREL was funded by the U.S. Department of Energy SunShot Foundational Program to Advance Cell Efficiency (F-PACE) under Contract No. DEAC36- 08-G028308. The Loughborough research was funded by UKERC through the EPSRC Supergen SuperSolar Hub.
History
School
- Mechanical, Electrical and Manufacturing Engineering
Research Unit
- Centre for Renewable Energy Systems Technology (CREST)
Published in
2015 IEEE 42nd Photovoltaic Specialist Conference (PVSC)Citation
ABBAS, A. ... et al, 2015. Structural and chemical characterization of the back contact region in high efficiency CdTe solar cells. IN: Proceedings of the 2015 IEEE 42nd Photovoltaic Specialist Conference (PVSC), New Orleans.Publisher
© IEEEVersion
- AM (Accepted Manuscript)
Publication date
2015Notes
© 2015 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.ISBN
9781479979448Publisher version
Language
- en
Location
New OrleansAdministrator link
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