Institute Silicon Photovoltaics
PersiST: Perowskit-Silizium Tandemsolarzellen – Perovskite-silicon tandem solar cells
In the project PersiST, we develop monolithically integrated perovskite/silicon solar cells, aiming at efficiencies above 29%. Furthermore, we aim at realizing tandem solar cells with an active area >100 cm².
A heterojunction silicon cell provides the base for the tandem cell. A very thin layer of transparent tin dioxide was deposited on this bottom cell, followed by 500 nm of perovskite as well as 200 nm of spiro-OMeTAD hole-conductor material. Thin MoO3 serves as a protective layer between this hole conductor and the transparent top electrode of ITO. Image: S. Albrecht / HZB
Goals
The sub-project at HZB focuses on developing such tandem cells on the basis of amorphous/crystalline heterojunction (SHJ) solar cells. HZB’s main tasks in the sub-project are
- To adapt the perovskite solar cell to the tandem structure, where the maximum process temperature is limited by the silicon heterojunction cell to ~250°C
- To optimize charge carrier transport and the electrical connection between the sub-cells
- To optimize the silicon solar cell as bottom cell in a tandem configuration
- To optimize the optical design of the whole system in order to maximize overall generation and to achieve current matching of the sub-cells
- To improve the stability of the perovskite cell
- To avoid critical materials
Project partners are
- Fraunhofer Institut für Solare Energiesysteme (ISE)
- Albert-Ludwigs-Universität Freiburg
- Helmholtz-Zentrum Berlin (Institut Silizium-Photovoltaik und Nachwuchsgruppe Perowskit Tandemsolarzellen)
- Heraeus
- Merck KGaA
- SolarWorld Innovations GmbH
The project is funded by the German Federal Ministry of Economic Affairs and Energy (BMWi), reference no. 0324037C.