The remarkable optoelectronic properties of hybrid organolead-halide perovskite materials hold tremendous promise for use as the active layer in low-cost solar cells and have attracted extraordinary attention for next-generation PV. For the promises of perovskite photovoltaics to be realized, however, dramatic advances in the understanding of their thermomechanical properties along with the development of material and solar cell design strategies to address their mechanical and chemical instabilities are required.
Our program focuses on solar cell design strategies along with improvements in the active and charge transport layers themselves to demonstrate mechanically and thermally robust working perovskite solar cells with major improvements in reliability and service lifetimes that can compete with CIGS and c-Si cells.
To that end and inspired by the compound eyes of an insect, we have developed a new concept in solar cell design, the compound solar cell (CSC), which addresses the intrinsic fragility of these materials with mechanically reinforcing internal scaffolds. The internal scaffold effectively partitions a conventional monolithic planar solar cell into an array of dimensionally scalable and reinforced individual perovskite cells.
Scaffold-reinforced compound solar cells inspired by the fly’s eye
We further demonstrate a scalable atmospheric plasma process to rapidly form mechanically robust photoactive perovskite films in open air at linear deposition rates exceeding 2 cm/s. In contrast to conventional solution-processing, our Rapid Spray Plasma Processing (RSPP) uses clean dry air to produce a combination of reactive species (photons, metastables, and radicals) and thermal energy to rapidly convert the perovskite film after spray-coating. We use RSPP to deposit pinhole-free, large-area, robust perovskite films with a ten-fold increase in fracture toughness and improved efficiency compared to control devices.
Large-area perovskite devices deposited by RSPP with an average efficiency of 13.4%
Current Research Projects
- Thermomechanical Properties of Perovskites and Charge Transport Layers
- Intrinsic Strengthening/Toughening of Perovskite Solar Cells
- Scaffold-Reinforced Compound Perovskite Solar Cells
- Scalable, Rapid Spray Processing of Perovskites
- Barrier Film Deposition of Perovskite Solar Cells for Improved Stability
- In-Situ X-Ray Characterization of Perovskite Crystallization and Degradation at SLAC