These solar cells use metal halide perovskite, an organic substance that resembles calcium titanium oxide and functions as a light-absorbing semiconductor to absorb incident sunlight and transform it into energy.
Cao added, “Perovskite solar cells offer high efficiency, exceeding 26% in laboratory conditions; low cost, using relatively inexpensive materials and simple manufacturing processes; flexibility, as they can be made on flexible substrates — such as plastic or metal foils — enabling the development of lightweight, flexible photovoltaic devices; and they can be scaled up to larger sizes. They have extraordinary potential as the next generation of photovoltaic technology.”
However, according to Cao, only a few research groups have produced perovskite solar cells with 25% or higher efficiency.
“Over the past years, many strategies have been adopted to improve the efficiency of perovskite solar cells. But achieving more than 25% efficiency is not yet common. As such, in this paper, we summarize recent developments in high-efficiency perovskite solar cells and highlight their effective strategies in crystal regulation, interface passivation and structural design of component layers,” Cao added.
According to Cao, these tactics might successfully address the primary reasons for low efficiency, which are faults caused by the preparation process and an inappropriate band structure. The material’s electron energy levels are referred to as the band structure. If it is too low, it will not be able to convert sunlight into energy effectively; if it is too high, it will experience the same problem.
Cao also mentioned the possibility of combining multiple types of solar cells to create “tandem solar cells,” which can surpass the efficiency limitations of a single type of solar cell. Furthermore, according to Cao, larger component manufacturing techniques need to be tuned to reach the same efficiencies as small-area fabrication techniques that need less than a tenth of a square centimeter.
Cao further added, “We believe that perovskite solar cells are one class of the most promising solar cells, and these efforts will ensure they can be commercialized and industrialized in the future. The future of perovskite solar cells is incredibly exciting, and the potential for further advancements is vast."
Additional collaborators include Liang Li and Liukang Bian from Soochow University’s School of Physical Science and Technology, as well as the Center for Energy Conversion Materials & Physics and the Jiangsu Key Laboratory of Thin Films. Cao is also connected to the Jiangsu Key Laboratory of Advanced Negative Carbon Technologies at Soochow University.
The study was sponsored by the Priority Academic Program Development of Jiangsu Higher Education Institutions and the National Natural Science Foundation of China.
Journal Reference:
Cao, F., et. al. (2024) Perovskite solar cells with high-efficiency exceeding 25%: a review. Energy Materials and Devices. doi:10.26599/EMD.2024.9370018.