Researchers design a water-splitting system assisted by monolithic perovskite-silicon tandem solar cells

• Scientists from Eindhoven University of Technology, Delft University of Technology as well as TNO (partner in Solliance) have actually made an integrated solar-assisted water-splitting system with a flow electrochemical cell and a monolithic perovskite-silicon tandem solar cell.

The team's work demonstrates exactly how a perovskite/silicon tandem cell can be incorporated with a water electrolyzer system. However, the group said that there are still several steps that need to be taken before commercialization is possible. As an example: upscaling the technology, addressing stability in better detail, and use even more earth-abundant drivers in the water-splitting response.

The researchers constructed an electrochemical (EC) flow cell with an active location of 4 cm2 as well as a two-compartment design. For the tandem solar cell, they combined a perovskite top cell and a lower cell based on a silicon heterojunction style. They said the electrochemical and solar batteries were wire-connected right into an integrated solar-assisted water-splitting system.

The team checked the design on the lab scale of 1 cm2, which in concept can be included larger areas - nonetheless, some of the deposition approaches will certainly need the be adapted.

The top cell is based upon a perovskite known as K0.05 Cs0.05( FA0.79 MA0.21) 0.90 Pb( I0.79 Br0.21) 3 with an energy bandgap of around 1.67 eV. They transferred the perovskite layer by means of atomic layer transferred (ALD) as well as used magnesium fluoride (MgF2) as an anti-reflecting coating. They developed the gadget with a substratum made of glass and an indium tin oxide (ITO), a tin( IV) oxide (SnO2) buffer layer, an electron transport layer made of buckminsterfullerene (C60), the perovskite layer, and also an opening transport layer made of carbazole (2PACz).

The research study group utilized plasma-assisted atomic layer deposition (ALD) to position a nickel oxide (NiO) interlayer between both cells and also an ITO substratum as the interconnection layer. They developed the bottom cell with a conventional design based upon amorphous silicon and also crystalline silicon layers with the addition an ITO substratum as well as a silver (Ag) metal contact.

The champ tandem gadget built with this arrangement accomplished a power conversion performance of 25.1%, an open-circuit voltage of 1.80 V, a short-circuit current of 17.9 mA cm − 2, as well as a fill factor of 0.78. According to the scientists, this system configuration has the ability to attain a solar-to-hydrogen (STH) effectiveness of over 21%.

" This STH performance is the greatest reported for systems operating at roughly 1-Sun equal light intensity, and also amongst the highest possible reported across a variety of combinations of EC and also PV systems," the group discussed.

" We are interested to work together with industrial partners who are interested in making this a technology," the scientists claimed. "The current design with making use of metals like indium (in the top electrode of the tandem cell), and platinum and ruthenium in the hydrogen and also oxygen evolution catalysts requires replacement by more earth-abundant and also cheaper options. Examples of such products are recognized, but we have actually not yet checked these."