Fraunhofer Institute for Solar Energy Systems ISEIn order to produce perovskite layers of the highest quality for perovskite-silicon tandem solar cells, we are pursuing a hybrid route combining vacuum evaporation and solution deposition. The two processes complement each other perfectly to enable the deposition of perovskite layers on micrometer-sized silicon pyramids. This has enabled us to achieve efficiencies of over 32%. We are now transferring this technology to our Pero-Si-SCALE technology platform using industrially scalable equipment for full wafer sizes (M12).
Linear Evaporation Processes for Large-Area, Industrially Scalable Perovskite-Silicon Tandem Solar Cells
LiverPool
SEM-Aufnahme einer Perowskit-Silizium-Tandemsolarzelle auf texturiertem Silizium. Der Perowskit-Absorber wurde mittels Verdampfung der anorganischen Komponenten und anschließender nasschemischer Infiltration der organischen Komponenten hergestellt.
Initial Situation
In recent years, significant increases in efficiency have continued to be achieved for crystalline silicon solar cells. Nevertheless, the efficiency of single-junction silicon solar cells is rapidly approaching the practical limit of approximately 27%. To further increase efficiency, different solar cell materials can be combined to form tandem solar cells, which reduce thermalization losses in the short-wave range and make better use of the solar spectrum.
Perovskite-silicon tandem technology has the potential to succeed the silicon cell, which currently dominates the market. Currently, the technology achieves its highest efficiency on small cell areas on a laboratory scale of 1 cm². The wet chemical method of spin coating is suitable for manufacturing cells of this size, but it is not scalable to industrial substrate sizes. In addition, it tends to be unsuitable for pyramid structures, such as those found on the front of silicon solar cells.
Objective
For industrial scalability, the focus of research is therefore shifting to vacuum-based evaporation methods. The scientific and technical objective of the LiverPool project is therefore to develop scalable processes for depositing perovskites and contact materials using vacuum technology for perovskite-silicon tandem solar cells.
Approach
An industrially scalable vapor deposition system will be procured and set up to enable the production of tandem solar cells at a throughput of several M12 wafers per hour. In addition, we are developing vapor deposition processes for the hybrid route, which will then be used in the production of perovskite-silicon tandem solar cells on M12 silicon wafers. This will create a unique technology platform for the further development of perovskite-silicon tandem technology.
Results
The selection and procurement of the linear evaporator has been completed and the first functional layers have been produced. We are currently working on transferring the process from the laboratory facilities to the new industrial evaporation plant.
Funding
The “ReNew” project is funded by the Federal Ministry of Economic Affairs and Energy (BMWE).
