Considerable efficiency gains in perovskite– silicon tandem solar batteries (such as that imagined here) can be achieved by adding a magnesium fluoride interlayer. Credit: © 2022 KAUST; Erkan Aydin
An extra metal fluoride layer makes it possible for charge separation and boosts efficiency in perovskite– silicon tandem solar cells.
Placing a metal fluoride layer in multilayered perovskite– silicon tandem solar cells can stall charge recombination and improve efficiency, King Abdullah University of Science & & Technology (KAUST) scientists have found.
Tandem solar cells that combine perovskite and silicon-based subcells in one gadget are anticipated to better capture and convert sunshine into electrical energy than their traditional single-junction silicon rivals. These problems together minimize the tandem cells open-circuit voltage, or optimum operating voltage, which restricts device efficiency.
Liu, De Wolf, and associates methodically examined the capacity of other metal fluorides, such as magnesium fluoride, as interlayer products at the perovskite/C60 interface of tandem cells. The magnesium fluoride interlayer efficiently promoted electron extraction from the perovskite active layer while displacing C60 from the perovskite surface.
Tandem solar cells that integrate perovskite and silicon-based subcells in one device are expected to much better capture and convert sunshine into electrical energy than their standard single-junction silicon rivals. These issues together minimize the tandem cells open-circuit voltage, or optimum operating voltage, which restricts gadget performance.
By including a layer of lithium fluoride in between the perovskite and the electron-transport layer, which normally comprises the electron-acceptor fullerene (C60), these performance issues might be partially dealt with. However, the gadgets end up being unstable since lithium salts easily liquefy and diffuse through surface areas. Lead author Jiang Liu, a postdoc in Stefaan De Wolfs group, states, “None of the gadgets have passed the basic test procedures of the International Electrotechnical Commission, triggering us to produce an option.”
Liu, De Wolf, and coworkers methodically investigated the potential of other metal fluorides, such as magnesium fluoride, as interlayer materials at the perovskite/C60 user interface of tandem cells. They thermally vaporized the metal fluorides on the perovskite layer to form an ultrathin uniform film with regulated density before including C60 and top contact components. The interlayers are likewise highly transparent and stable, in line with the inverted p-i-n solar cell requirements.
The magnesium fluoride interlayer effectively promoted electron extraction from the perovskite active layer while displacing C60 from the perovskite surface area. This reduced charge recombination at the interface. It also enhanced charge transport across the subcell.
The resulting tandem solar battery accomplished a 50 millivolt increase in its open-current voltage and a licensed supported power conversion efficiency of 29.3 percent– among the greatest performances for perovskite– silicon tandem cells, Liu states.
” Considering that the finest effectiveness is 26.7 percent for mainstream crystalline silicon-based single-junction cells, this ingenious innovation might bring substantial efficiency gains without contributing to the expense of fabrication,” Liu states.
To further check out the applicability of this innovation, the research group is developing scalable techniques to produce industrial-scale perovskite– silicon tandem cells with locations going beyond 200 square centimeters (31 square inches). “We are also establishing a number of strategies to obtain highly steady tandem gadgets that will pass the vital industrial stability procedures,” Liu states.
Referral: “Efficient and stable perovskite-silicon tandem solar batteries through contact displacement by MgFx” by Jiang Liu, Michele De Bastiani, Erkan Aydin, George T. Harrison, Yajun Gao, Rakesh R. Pradhan, Mathan K. Eswaran, Mukunda Mandal, Wenbo Yan, Akmaral Seitkhan, Maxime Babics, Anand S. Subbiah, Esma Ugur, Fuzong Xu, Lujia Xu, Mingcong Wang, Atteq ur Rehman, Arsalan Razzaq, Jingxuan Kang, Randi Azmi, Ahmed Ali Said, Furkan H. Isikgor, Thomas G. Allen, Denis Andrienko, Udo Schwingenschlögl, Frédéric Laquai, Stefaan De Wolf, 23 June 2022, Science.DOI: 10.1126/ science.abn8910.