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Perovskite/CIGS tandem solar cells: from certified 24.2% towards 30% and beyond

Publish Date: 23.12.2022

Category: Outstanding research achievements, Interdisciplinary research, Our contribution to sustainable development goals

Sustainable development goals: 7 Affordable and clean energy, 9 Industry, innovation and infrastructure, 11 Sustainable cities and communities, 13 Climate action (Indicators)

The research team from the Laboratory of Photovoltaics and Optoelectronics operating at the Faculty of Electrical Engineering, and researchers from Helmholtz Zentrum Berlin have constructed a record monolithic perovskite/CIGS tandem solar cell. Its certified power conversion efficiency (PCE) of 24.2% on 1 cm2 surface is one percentage point higher than the previous record value. The achievement results from improved passivation of the perovskite layer, both by applying a new layer for hole extraction to which the perovskite absorber is applied, and through passivation of the absorber itself and its surface.

In addition to the fabrication of the cell itself, the researchers’ article provides guidelines on further optical optimisation of perovskite/CIGS tandem solar cells. Optical simulations were used to determine that a 32% power conversion efficiency (PCE) could be achieved by selecting suitable layers and their thicknesses. By means of an energy yield model, which comprises both real data on both subcells and precise temperature- and light intensity-dependent data, the researchers evaluated the energy potential of this tandem technology. According to the calculations, an optimised perovskite/CIGS tandem solar cell can produce 30% more energy than a perovskite or CIGS single-junction solar cell. In addition, results confirm that the new technology of tandem solar cells is promising and define the necessary optical improvements for further growth in conversion efficiency.

Solar CIGS


Figure: Construction of the record, 24.2% perovskite/CIGS tandem solar cell and optical optimisation of the tandem structure with the aim of achieving a 30% PCE. Author: Dr Marko Jošt.



Doc. dr. Marko Jošt, dr. Eike Köhnen, dr. Amran Al-Ashouri, dr. Tobias Bertram, Špela Tomšič, dr. Artiom Magomedov, dr. Ernestas Kasparavicius, dr. Tim Kodalle, izr. prof. dr. Benjamin Lipovšek, prof. dr. Vytautas Getautis, prof. dr. Rutger Schlatmann, dr. Christian A. Kaufmann, prof. dr. Steve Albrecht, prof. dr. Marko Topič.


Jošt, M., Köhnen, E., Al-Ashouri, A., Bertram, T., Tomšič, Š., Magomedov, A., Kasparavicius, E., Kodalle, T., Lipovšek, B., Getautis, V., Schlatmann, R., Kaufman, C. A., Albrecht, S., Topič, M. (2022). Perovskite/CIGS Tandem Solar Cells: From Certified 24.2% toward 30% and Beyond. ACS Energy Letters, 7(4), 1298–1307. (JCR IF= 23.991).









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