Researchers from The Photovolatic and Optoelectronic Device Group at Oxford University have shown that perovskite-based concentrator photovoltaic devices (CPVs) may solve the issue of prohibitively high production costs while providing devices that perform comparably to commercialized silicon-based devices.
The devices are based on metal halide perovskites. The Oxford researchers, led by Henry Snaith, focused their search on a material that would be stable under high irradiance, and found the mixed-halide perovskite Fa0.83Cs0.17PbI2.7Br0.3 fit them best. The group found that their devices, when cooled constantly to maintain close to room temperature, retained 90% of their original efficiency after 150 hours spent under 10 Suns (10 kW/m2) of concentrated light.
Beyond 10 Suns of irradiance, the group observed a significant deterioration of their fill factor, a major contributor to the maximum power conversion efficiency of a solar cell. In their study, they have shown that the power conversion efficiency using the halide perovskite increased by 2.5% when the irradiance was increased from 1 Sun to 14 Suns , despite the deterioration of fill factor. The group’s proof-of-principle study therefore provides an opportunity to explore perovskites as an option for development of CPVs.
In the future, much more work must be done to bring CPVs to the market – in their article, the researchers emphasize that besides improving their fill factor, the stability of perovskites remains a concern for long-term use. Once researchers characterize the material, the development and optimization of the device and its optics will also affect the device’s commercialization.