German scientists have developed a technique for mass production of modern perovskite solar cells

The prestigious scientific journal Nature Energy has published an article by German scientists on the development of a technology for the scalable production of today’s most advanced perovskite solar cells. We are talking about a complete perovskite tandem solar cell, and both layers contain only the crystal structures of these minerals. This means that these items can be made easily and quickly without losing a high level of efficiency.

Tandem solar cells allow cells to operate across a wider power spectrum. For example, the upper silicon layer absorbs red and infrared spectra, while the lower perovskite layer absorbs blue and green. Last week, tandem perovskite cells set an efficiency record when the efficiency of photovoltaic cells exceeded 30% for the first time in history (for a 1 cm2 cell, which is significant because the efficiency decreases with increasing volume). The result is amazing, considering that one of the layers of this element is made of silicone, with all the resulting production features, including expensive processing.

In a new study, scientists at Karlsruhe Institute of Technology (KIT) set out to fabricate a tandem cell only from perovskite minerals with different bandgaps allowing the top and bottom layers of the cell to work with different spectra and avoid the use of silicon. The result was so good that scientists described evolution as a direct route to the mass production of pure perovskite tandem cells.

Using a combination of mechanical applications of solutions and vacuum deposition, the researchers created a cell with an efficiency of 19.1% for a net photocell area of ​​12.25 cm2 (excluding the frame and contact electrodes). When producing the same element with an area of ​​\u200b\u200b0.1 cm2 the efficiency was 23.5%. Expanding the scale of the manufacturing process only several times led to an incomplete decrease in efficiency by 5%. This means that process technology can be scaled up to mass without significant efficiency losses. At the same time, the main advantages of the manufacture of perovskite cells remain – treatment with liquid solutions, and with it the ability to create ferroelectric surfaces of complex shapes and on a flexible substrate.

Image source: Bahram Abdullah Negend, KIT

Source: Karlsruhe Institute of Technology. The research is freely available in Nature Energy at https://rdcu.be/cRW93.