Researchers at the National Renewable Energy Laboratory (NREL), along with collaborators from the SLAC National Accelerator Laboratory, University of Toledo, Princeton University, University of Arizona, University of Kentucky, and University of Colorado, have found away to improve the efficiency of perovskite solar cells by as much as 16%.

The effort involved combining a two-dimensional (2D) perovskite layer with a three-dimensional (3D) perovskite layer, which yielded a solar cell with improvements in both efficiency and stability.

Kai Zhu, a senior scientist in the Chemistry and Nanoscience Center at NREL and a corresponding author on the new paper, said that the melding of the 2D and 3D layers could boost the efficiency of the solar cell to about 24.7%.

The researchers based their work on another experimental approach involving adding a 2D layer based on bulky organic cations, or positively charged ions. That type of 2D perovskite structure, known as Ruddlesden-Popper, can inhibit the movement of charge carriers, thus limiting efficiency. The newer research, however, used a different 2D perovskite structure, known as Dion-Jacobson, in a metastable polymorph, which has shown greater stability and an ability to move charge carriers more freely.

The scientists compared the modified perovskite cell to a control sample. The modified cell showed only a 10% drop in efficiency after 1,000 hours of continuous operation. The control sample saw its efficiency decline by 43%.

The researchers said that the use of the metastable 2D structures represents a promising new chemical design that can be adapted by the solar industry to accelerate the development of efficient and stable perovskite solar cells.

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