Document Type


Publication Date




Publication Title

Journal of Energy and Power Technology






9 (1-9)


The effect of water ingress on the surface of the buffer layer of a Cu(In, Ga)Se2 (CIGS) solar cell was studied. Such degradation can occur either during the fabrication process, if it involves a chemical bath as is often the case for CdS, or while the modules are in the field and encapsulants degrade. To simulate the impact of this moisture ingress, devices with a structure sodalime glass/Mo/CIGS/CdS were immersed in deionized water. The thin films were then analyzed both pre and post water soaking. Dynamic secondary ion mass spectroscopy (SIMS) was performed on completed devices to analyze impurity diffusion (predominantly sodium and potassium) and to assess potential degradation mechanisms. The results were compared to device measurements, which indicate a degradation of all device parameters due to an increase in the total and peak trap densities, as shown by simulation. This is potentially due to a modification of the sodium profile in the bulk CIGS, with a decrease content after water soaking or because the oxygen profile increased in the bulk CIGS after water soaking.


© 2021 by the authors.

This is an open access article distributed under the conditions of the Creative Commons Attribution 4.0 International License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium or format, provided the original work is correctly cited.

Original Publication Citation

Poudel, D., Belfore, B., Karki, S., Rajan, G., Soltanmohammad, S., Rockett, A. & Marsillac, S. (2021) Assessment of Cu(In, Ga)Se₂ solar cells degradation due to water ingress effect on the CdS buffer layer. Journal of Energy and Power Technology, 3(1), 1-9, Article 9.


0000-0001-8069-8602 (Poudel), 0000-0002-3173-8505 (Karki), 0000-0003-4000-6928 (Rajan), 0000-0003-0826-8119 (Marsillac)