I-Corps: Heliotrope Light-shifting Thin Films to Increase the Performance of Silicon Solar Panels

The broader impact/commercial potential of this I-Corps project is the development of light-shifting thin films that convert wasted ultraviolet (UV) light into useful infrared light to increase the performance of silicon solar panels. Solar panels are efficient in the infrared region but do not convert UV light efficiently. By transforming the sunlight, the proposed technology can deliver a power boost of 8% to 15%, without changing the underlying solar panel technology. This thin film technology adds one additional step to the production process, and may be integrated into the current photovoltaic manufacturing process. The proposed technology may help to lower manufacturing costs (dollar per watt) for manufacturers and lower cost of electricity for end users. In addition, the technology may increase the adoption of solar energy and accelerate the transition to a sustainable future.This I-Corps project is based on the development of luminescent downshifting thin film materials that convert ultraviolet (UV) light into near-infrared light. The proposed thin films are made of a perovskite, Cs2AgBiBr6, doped with a small amount of Ytterbium (Yb), a rare earth metal element. As the perovskite absorbs a UV photon, it transfers energy to Yb, which then emits in the infrared region. Results using the proposed thin film have demonstrated a light conversion efficiency of 95%; i.e., 95% of incoming ultraviolet light is converted to infrared light. The light conversion efficiency may be improved further to the maximum values of 200%, which means one ultraviolet photon is converted to two infrared photons (1:2 thin film). Using this light-shifting technology, it may be possible to improve the silicon solar panel’s power output from 8% to 15%.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.