Highly Efficient All-Perovskite Tandem Solar Cells with Reduced Recombination Losses and Improved Stability by Innovative Characterization (HIPSTER-PRO)

• Applicants: Professor Dr. Steve Albrecht; Dr. Felix Lang, since 8/2023; Professor Dr. Thomas Riedl; Professor Henry Snaith, Ph.D.
• Subject Area: Experimental Condensed Matter Physics ; Physical Chemistry of Solids and Surfaces, Material Characterisation
• Term: since 2019
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 424709669

The recent improvements of the photovoltaic performance of metal-halide perovskites give promise for the realization of all-perovskite tandem solar cells with power conversion efficiencies exceeding the Shockley-Queisser limit for single junctions. Until today, very promising monolithic all-perovskite tandem cells with experimental efficiency values of 26.4% have been demonstrated and various theoretical and semi-empirical estimates predict values well above 30%.In the proposed second period of the highly successful project HIPSTER, the same four partners from the first period: Helmholtz-Center (HZB), University of Oxford (UOx), University of Potsdam (UPo), and University of Wuppertal (UWu) will push the characterization and understanding of this tandem solar cell technology to the next level: Work in the second phase will be devoted to the understanding and suppression of compositional instabilities and overall degradation mechanisms as well as to the further reduction of non-radiative recombination losses. While the team has already proven its ability to highlight various sub-cell limitations by detailed analysis and to develop highly efficient tandem solar cells in the first phase, in the second phase the photo-chemical stability of perovskite absorbers needs to be analysed and further increased. The work on stability will be complemented by innovative characterization methods such as sub-cell characterization directly for tandem solar cells to quantify recombination and ionic losses from different interfaces and contact materials directly within the tandem stack. As such, we will be able to identify the best suited contact, interconnection, and interlayer materials as well as passivation strategies for highest tandem performance. Ultimately, we strive to demonstrate stable monolithic all-perovskite tandem devices by advanced analyses and consequent reduction of loss mechanisms to approach the performance of perovskite-silicon based tandem solar cells.

• DFG Programme: Priority Programmes
• Subproject of: SPP 2196: Perovskite semiconductors: From fundamental properties to devices
• International Connection: United Kingdom
• Ehemaliger Antragsteller: Dr. Martin Stolterfoht, until 7/2023