Workshop on “Microstructure Characterization and Modeling for Solar Cells”
© HZB
The winter workshop was held in a beautiful location at Spitzingsee (Bayern) from 22. to 26. february 2015 and organised by Helmholtz Virtual Institute "Microstructure Control for Thin-Film Solar Cells". The next winter workshop will be planned for 2017.
About the Helmholtz Virtual Institute „Microstructure control for thin film solar cells“
In this Virtual Institute (VI), the formation of structural defects and related strain during the growth of thin film solar cells will be investigated by combining various experimental as well as simulation approaches. The aim of this Virtual Institute is to understand and control the formation of structural defects and strain during the growth of polycrystalline silicon (poly-Si) and Cu(In,Ga)Se2 (CIGSe) thin films by optimized growth parameters. Unique experimental in-situ techniques for monitoring the growth process of these thin films, such as X-ray diffraction and fluorescence analysis at a synchrotron beamline, are combined with phase field modeling as well as density-functional theory and molecular dynamics simulations.
- Funding: Helmholtz Association
- Leading Center: Helmholtz-Zentrum Berlin für Materialien und Energie
- Partners involved: TU Berlin, FU Berlin, TU Darmstad, University of Oxford (UK), ETH Zürich (Schweiz), SuperStem (UK)
- Speakers: Prof. Dr. Susan Schorr, HZB
- Duration: Nov. 2012 till Oct. 2017
- CIGS-perovskite tandem cell achieves record efficiency of 25.5 %A Berlin-based team from HZB and Center for the Science of Materials Berlin (CSMB) at the Humboldt-Universität zu Berlin has set a new record for a tandem solar cell. Using a combination of a CIGS semiconductor layer and perovskite, along with several optimised intermediate layers, they were able to convert 25.5% of sunlight into electrical energy. The previous record for this combination of materials and this size of cell stood at 24.6%. The new record has been certified and is visible in the prestigious Solar Cell Efficiency Tables (the "Green Tables"), which serve as the definitive ledger for the global photovoltaic community.
- Disorder creates new properties in compound semiconductorsAn international research team has demonstrated that the intrinsic disorder of the compound semiconductor CuInSnS₄ can be exploited to influence its optical properties. While the atomic vibrations also sense the local disorder, their response is averaged over many different local environments and therefore appear isotropic, as expected for a cubic crystal. In contrast, the optical excitations, known as excitons, are much more sensitive to the local arrangement of atoms. Surprisingly, they show a direction-dependent optical response even though the average crystal structure is cubic. These findings shed new light on the relationship between disorder and material properties, opening up new options for targeted 'disorder engineering' in optoelectronic and photocatalytic devices.
- Perovskite solar cells: Predictions of long-term stabilityReliable statements about the long-term stability of perovskite solar cells are still difficult to make. However, a new study by Dr Carolin Ulbrich’s team, published in the renowned journal Joule, highlights which methods are useful for this purpose and identifies areas where further research is needed.