Reliable wet-chemical cleaning of natively oxidized high-efficiency Cu(In,Ga)Se-2 thin-film solar cell absorbers
(2014) In Applied Physics Reviews 116(23).- Abstract
- Currently, Cu-containing chalcopyrite-based solar cells provide the highest conversion efficiencies among all thin-film photovoltaic (PV) technologies. They have reached efficiency values above 20%, the same performance level as multi-crystalline silicon-wafer technology that dominates the commercial PV market. Chalcopyrite thin-film heterostructures consist of a layer stack with a variety of interfaces between different materials. It is the chalcopyrite/buffer region (forming the p-n junction), which is of crucial importance and therefore frequently investigated using surface and interface science tools, such as photoelectron spectroscopy and scanning probe microscopy. To ensure comparability and validity of the results, a general... (More)
- Currently, Cu-containing chalcopyrite-based solar cells provide the highest conversion efficiencies among all thin-film photovoltaic (PV) technologies. They have reached efficiency values above 20%, the same performance level as multi-crystalline silicon-wafer technology that dominates the commercial PV market. Chalcopyrite thin-film heterostructures consist of a layer stack with a variety of interfaces between different materials. It is the chalcopyrite/buffer region (forming the p-n junction), which is of crucial importance and therefore frequently investigated using surface and interface science tools, such as photoelectron spectroscopy and scanning probe microscopy. To ensure comparability and validity of the results, a general preparation guide for "realistic" surfaces of polycrystalline chalcopyrite thin films is highly desirable. We present results on wet-chemical cleaning procedures of polycrystalline Cu(In1-xGax)Se-2 thin films with an average x = [Ga]/([In] + [Ga]) = 0.29, which were exposed to ambient conditions for different times. The hence natively oxidized sample surfaces were etched in KCN- or NH3-based aqueous solutions. By x-ray photoelectron spectroscopy, we find that the KCN treatment results in a chemical surface structure which is - apart from a slight change in surface composition - identical to a pristine as-received sample surface. Additionally, we discover a different oxidation behavior of In and Ga, in agreement with thermodynamic reference data, and we find indications for the segregation and removal of copper selenide surface phases from the polycrystalline material. (C) 2014 AIP Publishing LLC. (Less)
Please use this url to cite or link to this publication:
https://lup.lub.lu.se/record/4941629
- author
- Lehmann, Jascha ; Lehmann, Sebastian LU ; Lauermann, Iver ; Rissom, Thorsten ; Kaufmann, Christian A. ; Lux-Steiner, Martha Ch. ; Baer, Marcus and Sadewasser, Sascha
- organization
- publishing date
- 2014
- type
- Contribution to journal
- publication status
- published
- subject
- in
- Applied Physics Reviews
- volume
- 116
- issue
- 23
- article number
- 233502
- publisher
- American Institute of Physics (AIP)
- external identifiers
-
- wos:000346634500011
- scopus:84920280507
- ISSN
- 1931-9401
- DOI
- 10.1063/1.4903976
- language
- English
- LU publication?
- yes
- id
- 4096ef0a-0a37-4574-9978-8015b155eac5 (old id 4941629)
- date added to LUP
- 2016-04-01 10:57:01
- date last changed
- 2023-10-12 18:04:35
@article{4096ef0a-0a37-4574-9978-8015b155eac5,
abstract = {{Currently, Cu-containing chalcopyrite-based solar cells provide the highest conversion efficiencies among all thin-film photovoltaic (PV) technologies. They have reached efficiency values above 20%, the same performance level as multi-crystalline silicon-wafer technology that dominates the commercial PV market. Chalcopyrite thin-film heterostructures consist of a layer stack with a variety of interfaces between different materials. It is the chalcopyrite/buffer region (forming the p-n junction), which is of crucial importance and therefore frequently investigated using surface and interface science tools, such as photoelectron spectroscopy and scanning probe microscopy. To ensure comparability and validity of the results, a general preparation guide for "realistic" surfaces of polycrystalline chalcopyrite thin films is highly desirable. We present results on wet-chemical cleaning procedures of polycrystalline Cu(In1-xGax)Se-2 thin films with an average x = [Ga]/([In] + [Ga]) = 0.29, which were exposed to ambient conditions for different times. The hence natively oxidized sample surfaces were etched in KCN- or NH3-based aqueous solutions. By x-ray photoelectron spectroscopy, we find that the KCN treatment results in a chemical surface structure which is - apart from a slight change in surface composition - identical to a pristine as-received sample surface. Additionally, we discover a different oxidation behavior of In and Ga, in agreement with thermodynamic reference data, and we find indications for the segregation and removal of copper selenide surface phases from the polycrystalline material. (C) 2014 AIP Publishing LLC.}},
author = {{Lehmann, Jascha and Lehmann, Sebastian and Lauermann, Iver and Rissom, Thorsten and Kaufmann, Christian A. and Lux-Steiner, Martha Ch. and Baer, Marcus and Sadewasser, Sascha}},
issn = {{1931-9401}},
language = {{eng}},
number = {{23}},
publisher = {{American Institute of Physics (AIP)}},
series = {{Applied Physics Reviews}},
title = {{Reliable wet-chemical cleaning of natively oxidized high-efficiency Cu(In,Ga)Se-2 thin-film solar cell absorbers}},
url = {{http://dx.doi.org/10.1063/1.4903976}},
doi = {{10.1063/1.4903976}},
volume = {{116}},
year = {{2014}},
}