German Researchers Develop 18% Efficient Large-area Perovskite Module

Advancements in perovskite technology have been happening at a rapid rate in the last few years but the area is still riddled with challenges related to size, efficiency and stability of the cells. Fresh positive news has come from Germany where researchers claim to have resolved possibly the biggest hindrance in the mass application of perovskite material- the unavailability of large-area perovskite PV modules – by scaling up from the perovskite cell to the module level without any efficiency loss.

Scientists at Germany’s Karlsruhe Institute of Technology (KIT) claim that they have achieved an efficiency of 18% for a perovskite solar module solar module with an area of ​​4cm2. This a world record for a vacuum-processed perovskite panel. On a module surface of ​​more than 50 centimeters squared, they achieved an efficiency of up to 16.6%, and on a module with an area of 4 centimeters squared, the efficiency achieved was 18%. The perovskite cells were connected in series to form large-area solar modules using the so-called monolithic series connection, with structuring lines being introduced during the deposition of a cell’s individual layers, which were all deposited through a vacuum process.

KIT researcher Tobias Abzieher, a post-doctoral researcher in the field of novel concepts of photovoltaics at the National Renewable Energy Laboratory (NREL), said, “The major advantages of vacuum deposition with regard to the production of efficient solar modules, are the ease with which the processes can be controlled, the low number of process parameters and, in particular, the independence of the deposition mechanism from the coating surface,” and noted that the process was used in combination with a laser technique for the monolithic series connection. With the combination of vacuum processing and laser ablation, the scientists achieved an efficiency of up to 16.6% on a module surface of ​​more than 50cm2 and 18% on a module with an area of 4cm2.

David Ritzer, a Ph.D. Student studying investigation and optimisation of pulsed laser ablation for varying scribing processes onto differently fabricated perovskite-based thin-film PV modules, said, “Despite the enlargement of the device’s area by a factor of over 500, almost no loss of efficiency can be observed.”

KIT claims that with this new approach, it has succeeded in reducing the scaling losses in perovskite solar modules to values that are close to those of cadmium telluride (CdTe) or copper-indium-gallium-diselenide (CIGS) modules. In the future, the researchers will work on optimizing the solar cell layer stack and on further reducing the dead areas. Another researcher, Ulrich Paetzold, said that if the potential of their technology is fully exploited, the production of perovskite solar modules with efficiencies of well over 20%, even on even larger areas, will become an achievable goal in a timely manner.

Perovskites have many advantages over silicon wafers which are currently used for making solar PV modules. Pervoksites are lighter, smaller, and cheaper, and also physically flexible, with the manufacturing process having smaller environmental footprint. This is why scientists have been working to fill the technology gap behind their few limitations. For instance, in December last year, a new paper entitled ‘Unraveling the compositional heterogeneity and carrier dynamics of alkali cation doped 3D/2D perovskites with improved stability’, was published in the journal Materials Advances by scientists at the U.S. National Institute of Standards and Technology, offering a new method- rubidium doping & 2D capping- to enhance the stability of perovskite solar cell technologies. If innovation continues to smoothen their rough edges, perovskites could soon revolutionise the solar PV industry.

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Soumya Duggal

Soumya Duggal

Soumya is a master's degree holder in English, with a passion for writing. It's an interest she has directed towards environmental writing recently, with a special emphasis on the progress being made in renewable energy.