An inventive inverted Perovskite solar cell using Lewis base molecules for surface passivation has been discovered by US-Canadian research. In order to passivate surface flaws in the perovskite, Lewis-based materials are frequently utilised in perovskite solar cells.
Energy level alignment, hysteresis behaviour, interfacial recombination kinetics, and operational stability are all positively impacted by the procedure.
Lewis basicity, which is inversely correlated to electronegativity, “determines the binding energy and the stabilisation of interfaces and grain boundaries,” according to the expert.
The molecules have a strong bond with the cell’s interface and are powerful.
“A Lewis base molecule that contains two electron-donating atoms may be able to attach to and span ground boundaries. Providing the possibility improves the adhesion and increases the mechanical durability of Perovskite solar cells.
How Does It Work?
One of the most promising halide perovskites is passivated by the Lewis base molecule 1,3-bis propane.
At the Perovskite interface and the Perovskite surface region, they did, however, apply the Perovskite layer on a nickel (II) oxide-based hole transparent layer (HTL) that was doped with DPP (NiOx).
However, the crystallinity of the Perovskite films increased and certain DPPP molecules were observed to be redissolved and separated.
They claimed that this activity increased the mechanical toughness of the Perovskite/NiOx contact.
The cell was built using the Perovskite layer, a delicate layer of phenethylammonium iodide (PEAI), an electron transport layer of buckminsterfullerene (C60), a tin (IV) oxide (SnO2) buffer layer, and a metal contact made of silver.
Also, the hole transport layer was based on nickel oxide (NiOx), and the substrate was built of glass and tin oxide (FTO) (Ag).
Performance of the DPPP-doped solar cell was contrasted with an untreated control device.
The doped cell obtained a 1.16 V open-circuit voltage, an 82% fill factor, and a 24.5% efficiency in power conversion.
The undoped device, however, had a 22.6% efficiency. A 79% fill factor and a 1.11V open circuit voltage are in contrast.
The reduction in defect density at the NiOx/Perovskite front interface following DPPP treatment, according to the scientists, was “confirmed by the improvement of fill factor and open circuit voltage.”
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The researchers also developed a doped cell with a 1.05cm square active area that had to be capable of up to a 23.9% power conversion efficiency and show no degradation after 1,500 hours.
“Using DPPP, under ambient settings, that is no additional heating-the overall power conversion efficiency of the cell stayed high for almost 3,500 hours,” claims researcher Chongwen Li.
Furthermore, he added that “this is a substantial increase” because “the Perovskite solar cells that have been previously published in the literature tend to suffer a large decline in their efficiency after 1,500 to 2,000 hours.”
In the paper “Rational design of Lewis base molecules for stable and efficient inverted Perovskite solar cells,” the team currently working on this subject applied for a patent for a DPPP technique, which offers the cell technology.