C
Christian A. Kaufmann
Researcher at Helmholtz-Zentrum Berlin
Publications - 210
Citations - 4880
Christian A. Kaufmann is an academic researcher from Helmholtz-Zentrum Berlin. The author has contributed to research in topics: Thin film & Copper indium gallium selenide solar cells. The author has an hindex of 38, co-authored 205 publications receiving 4045 citations. Previous affiliations of Christian A. Kaufmann include University of Oxford & Chemnitz University of Technology.
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Journal ArticleDOI
Conformal monolayer contacts with lossless interfaces for perovskite single junction and monolithic tandem solar cells
Amran Al-Ashouri,Artiom Magomedov,Marcel Roß,Marko Jošt,Martynas Talaikis,Ganna Chistiakova,Tobias Bertram,José A. Márquez,Eike Köhnen,Ernestas Kasparavicius,Sergiu Levcenco,Lidón Gil-Escrig,Charles J. Hages,Rutger Schlatmann,Bernd Rech,Bernd Rech,Tadas Malinauskas,Thomas Unold,Christian A. Kaufmann,Lars Korte,Gediminas Niaura,Vytautas Getautis,Steve Albrecht,Steve Albrecht +23 more
TL;DR: In this paper, hole-selective contacts for perovskite solar cells (PSCs) are introduced, which outperform all typical p-contacts in versatility, scalability and PSC power-conversion efficiency.
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Interpretation of admittance, capacitance-voltage, and current-voltage signatures in Cu(In,Ga)Se2 thin film solar cells
TL;DR: In this article, a series of CIGS thin film solar cells with differently prepared heterojunctions has been investigated by admittance spectroscopy, capacitancevoltage (CV) profiling, and temperature dependent current-voltage measurements, and the results strongly contradict the common assignment of the N1 response to a donor defect at or close to the heterointerface.
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21.6%-Efficient Monolithic Perovskite/Cu(In,Ga)Se2 Tandem Solar Cells with Thin Conformal Hole Transport Layers for Integration on Rough Bottom Cell Surfaces
Marko Jošt,Tobias Bertram,Dibyashree Koushik,José A. Márquez,Marcel A. Verheijen,Marc Daniel Heinemann,Eike Köhnen,Amran Al-Ashouri,Steffen Braunger,Felix Lang,Bernd Rech,Thomas Unold,Mariadriana Creatore,Iver Lauermann,Christian A. Kaufmann,Rutger Schlatmann,Steve Albrecht +16 more
TL;DR: In this paper, a monolithic perovskite/CIGSe tandem solar cell was proposed to increase the power conversion efficiency (PCE) of conventional single-junction photovoltaic devices.
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The influence of Na on low temperature growth of CIGS thin film solar cells on polyimide substrates
Raquel Caballero,Christian A. Kaufmann,Tobias Eisenbarth,M. Cancela,Raik Hesse,Thomas Unold,A. Eicke,Reiner Klenk,H.-W. Schock +8 more
TL;DR: In this paper, the influence of Na on the properties of CIGS absorber layers and finished solar cell devices on polyimide substrates was studied, and a stronger Ga-gradient and a decrease of grain size were observed when the Na content increases.
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Experimental indication for band gap widening of chalcopyrite solar cell absorbers after potassium fluoride treatment
Paul Pistor,Dieter Greiner,Christian A. Kaufmann,Stephan Brunken,Mihaela Gorgoi,Alexander Steigert,Wolfram Calvet,Iver Lauermann,Reiner Klenk,Thomas Unold,Martha Ch. Lux-Steiner +10 more
TL;DR: In this article, compositional and electronic changes of the Cu(In,Ga)Se2 absorber surface as a result of a post deposition treatment with KF (KF PDT) were reported.