New layout strategies to improve the stability and efficiency of bifacial perovskite solar cells

• Solar cells based upon perovskites, calcium titanium oxide minerals or compounds with similar structures, are amongst one of the most appealing emerging energy options. Over the past couple of years, engineers and material researchers have been exploring the capacity of solar mini-modules (i.e., little cells that can be utilized to develop larger-scale solar panels) made from perovskite bifacial structures.

As recommended by their name, these flat structures have perovskite products on both their front and rear end, with the very first harvesting straight sunlight and the latter light that is assessed surfaces (i.e., albedo light). While solar mini modules based on perovskite bifacial structures might achieve higher power conversion effectiveness (PCEs) than traditional perovskite solar cells, properly making them has thus far shown challenging.

Researchers at University of North Carolina at Chapel Hill just recently presented new design strategies that can help to boost the effectiveness and stability of bifacial perovskite solar cells. Utilizing these strategies, laid out in Nature Energy, they created new solar mini-modules that achieved impressive efficiencies.

" Perovskites solar cells are growing with quickly climbing performances and commercialization of them are moving fast worldwide, but there are still numerous staying difficulties to get rid of, including low stability and the derate of efficiency when moving from lab-scale tiny cells to large-area modules," Jinsong Huang, among the researchers that executed the study, told Tech Xplore. "One uncertainty is whether the cost-saving of using low-priced perovskites and deposition processes is sufficient to compete with fossil fuel-based energy."

By at the same time gathering both straight sunlight and albedo light, bifacial solar cells can enhance the energy yield of solar modern technologies. So far, nonetheless, researchers only created a couple of bifacial perovskite cells and modules, and existing ones exhibited far reduced efficiencies than their mono-facial equivalents.

" The objective of our recent work was to show perovskite bifacial minimodule with high energy return and lengthy operational lifetime," Huang said. "The major strategies we suggest for the style optimization of bifacial perovskite modules include a freshly made module structure and back electrode, including hydrophobic additives for boosted dampness stability, and boosting long-wavelength light absorption with ingrained dielectric nanoparticles."

Huang and his coworkers first of all created a bifacial structure in which individual sub-cells are connected by indium tin oxide (ITO), and with silver grids that are separated by an ideal space on the rear ITO electrode to decrease resistance loss (i.e., the loss of electric energy that can happen when an existing flows inside wires). This design is straightforward and scalable, which indicates that it could make it possible for the large-scale construction and commercialization of perovskite bifacial mini-modules.

" We additionally located that including tris( pentafluorophenyl) borane (TPFB) as an additive in the red transport layer undoubtedly reduce the damage of wetness to the perovskite film throughout the procedure of SnO2 deposition," Huang explained.

" Besides, the addition of TPFB reduced resistivity of hole transport layer and boosted the energy placement. Lastly, we introduced nanoparticles (NPs) into the perovskite to scatter the event sunlight, therefore boosting the optical course to conquer their absorption loss particularly in long wavelength array in bifacial modules."

Using their recommended layout, the scientists developed tiny area bifacial perovskite solar cells that achieved a power generation density of 26.4 mW cm-2 and bifacial minimodules that accomplished a power generation density of 23 mW cm-2, when subjected to route sunlight on one side and an albedo lighting of 0.2 on the other. These outcomes are significantly better than the power generation densities displayed by both formerly established perovskite single-junction solar cells and minimodules.

Extremely, the prototype minimodule established by the team was additionally discovered to accomplish a remarkably functional stability, only shedding 3% of its preliminary efficiency after working for greater than 6,000 hours. Integrated, the layout strategies presented by this team of researchers could therefore lead the way in the direction of the large-scale fabrication of extremely effective and stable solar power services based on bifacial perovskite structures.

" While some companies may currently be dealing with marketing perovskite bifacial solar cells, this work affirms the promising capacity of these bifacial structures," Huang added. "We would now like to recognize new strategies to consistently improve the energy yield and stability of bifacial perovskite solar modules."