US EPA

4849593 

Journal Article 

Stability of Cu(In,Ga)Se-2 solar cells: A literature review 

Theelen, M; Daume, F 

2016 

1 

Solar Energy
ISSN: 0038-092X 

133 

586-627 

10.1016/j.solener.2016.04.010 

WOS:000377733300050 

As Cu(In,Ga)Se-2 (CIGS) photovoltaic (PV) technology matures to production on an industrial scale, its long-term stability becomes increasingly important: The electric yield and thus the revenue of a PV system depend on both the initial conversion efficiency as well as its development over time. Increasing this long-term stability by understanding and lowering the degradation of this PV technology is therefore a key strategy for CIGS market success. Furthermore, increasing the long-term stability of individual solar cells allows to lowering the demands and thus the cost of barrier materials within CIGS modules.



Many authors have contributed to this subject over the years. In this review article, we have studied 143 publications related to the stability of CIGS solar cells and (mini-)modules. This review focuses on the behavior of unencapsulated CIGS solar cells and (mini-) modules when exposed to different accelerated lifetime tests, like elevated temperature and humidity. We describe the changes in electrical and physical performance due to these tests, as well as the chemical reactions that are causing these changes.



Additionally, the state of knowledge on the influence of these tests on the individual layers of the CIGS solar cell has been summarized. Dedicated chapters review the stability of both, the transparent conducting ZnO:Al front contact and the molybdenum back contact, as well as on the CIGS and buffer layers. Stability issues related to the module design of CIGS PV, like the application of grid structures and monolithic interconnection, are discussed as well. (C) 2016 Elsevier Ltd. All rights reserved. 

CIGS; Damp heat; Degradation; Long term; Molybdenum; Photovoltaics; Review; Stability; Zinc oxide