A new stable and cost-cutting type of perovskite solar cell

Hybrid organic–inorganic methylammonium lead halide perovskites have attracted intense attention for thin-film photovoltaics, due to their large absorption coefficient, high charge carrier mobility and diffusion length. However, these cells are also costly because of the hole-transportation layer, which demands high purity materials and complicated fabrication procedures.

A team of scientists at the Michael Grätzel Center for Mesoscopic Cells of Huazhong University in China have successfully manufactured a perovskite solar cell that does not need a hole-transportation layer. The solar cell shows comparative energy conversion efficiency (12.8%) and was shown to be stable for over 1000 hours in direct sun exposure.

The scientists fabricated the new solar cell by drop-casting a solution of lead iodide, methylammonium iodide, and 5-ammoniumvaleric acid iodide through a porous carbon film. The solar cell’s scaffolding was made using a double layer of titanium dioxide and zirconium dioxide covered by a porous carbon film. The resulting mixed-cation perovskite crystals showed higher electrical charge efficiency than conventional perovskite cells. The triple layer also resulted in better surface contact, leading to considerably high stability.

Perovskite solar cells are ideally placed to meet the increasing demands for renewable energy in the future. This breakthrough innovation addresses one of their major limiting factors, and paves the way for a new, cost-effective branch of development in this type of solar cell.

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This work represents a collaboration between EPFL’s Laboratory Of Photonics And Interfaces and the Michael Grätzel Center for Mesoscopic Cells of Huazhong University (China).

Reference

Mei A, Li X, Liu L, Ku Z, Liu K, Rong Y, Xu M, Hu M, Chen J, Yang Y, Grätzel M, Han H. A hole-conductor–free, fully printable mesoscopic perovskite solar cell with high stability. Science 345:6194 DOI: 10.1126/science.1254763