Japanese scientists develop new perovskite process

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One of many research groups the world over working to unlock the commercial potential of perovskite solar cells, researchers from the Energy Materials and Surface Sciences Unit at OIST have developed a process, which they say could be scaled up for use in commercial production.

The low-cost, high efficiency potential of perovskites has long been known, and research has pushed the development of the technology at an impressive rate. “Research on perovskite cells is very promising,” says OIST Professor Yabing Qi. “In only nine years, the efficiency of these cells went from 3.8 % to 23.3%.”

The device developed by the OIST group, described in the article ‘Gas-solid reaction based over one-micrometer thick stable perovskite films for efficient solar cells and modules, and published in the journal Nature Communications, was created using a gas-solid reaction-based technique, in which the substrate is first coated with a layer of hydrogen lead triiodide incorporated with a small amount of chlorine ions and methylamine gas, which the researchers say allowed them to make uniform, reproducible panels.

Key to their method, says OIST, was the use of a 1-micron thick active perovskite layer. This thicker coating is said to boost stability of the solar cells, as well as simplifying the production processes, thereby lowering costs. The researchers were able to scale up their process from a prototype measuring 0.1mm², to a module based on 5x5cm² cells. Although scaling up the size significantly reduced the cell efficiency, from 19.1% to 15.3%, the team says it will now focus on improving this, and is confident that the process will be ready for commercial use in the coming years.

U.K.-headquartered perovskite specialists, Oxford PV, meanwhile, appear to be leading the charge for commercialization of perovskite technology, having recently announced plans for a research partnership targeting 37% efficient perovskite cells. The company previously told pv magazine that it has successfully scaled up its perovskite on silicon tandem cells to ‘full size’ 156 x 156mm, with only “a small difference” in efficiency, compared with research sized devices.