Efficient, stable silicon tandem cells enabled by anion-engineered wide-bandgap perovskites

Abstract

Maximizing the power conversion efficiency (PCE) of perovskite/silicon tandem solar cells that can exceed the Shockley-Queisser single-cell limit requires a high-performing, stable perovskite top cell with a wide bandgap. We developed a stable perovskite solar cell with a bandgap of ~1.7 electron volts that retained more than 80% of its initial PCE of 20.7% after 1000 hours of continuous illumination. Anion engineering of phenethylammonium-based two-dimensional (2D) additives was critical for controlling the structural and electrical properties of the 2D passivation layers based on a lead iodide framework. The high PCE of 26.7% of a monolithic two-terminal wide-bandgap perovskite/silicon tandem solar cell was made possible by the ideal combination of spectral responses of the top and bottom cells.

Solid-phase hetero epitaxial growth of α-phase formamidinium perovskite

“…From the scanning TEM (STEM) images in Supplementary Fig. 5a, b, we identified the layered perovskite at the grain boundaries and surface of the FAPbI 3 grains before and after the heat-treatment with its characteristic interplanar spacing of around 7.25 Å corresponding to the (002) plane 20,21 . Figure 2f shows the magnified interface region between the layered perovskite and the δ-FAPbI 3 phase before the phase conversion process.…”

Identifying Photoinduced Dipolar Polarization and Orbit–Orbit Interaction between Excitons in Organic–Inorganic Hybrid Perovskites

“…Organic-inorganic hybrid perovskites have been heavily investigated owing to their remarkable photovoltaic performance and low-cost solution processability. [1][2][3][4][5] Perovskites with ABX 3 structure are typically composed of organic cations at A site and inorganic cages BX 6 (B = Pb 2+ , Sn 2+ ; X = I − , Br − , Cl − ). [6,7] Owing to the small rotational energy and nonspherical nature, the organic cations with intrinsic dipole moment induce a dipolar polarization.…”

Recombination junctions for efficient monolithic perovskite-based tandem solar cells: physical principles, properties, processing and prospects

“…69 When the NiO x surface was modified with poly-TPD and PFN, the V OC improved significantly; similar improvements were obtained by replacing the NiO x altogether with PTAA. 55,56,70,71 Conversely, when the TCO-based RJ stack is inverted to a-Si(p + )/TCO (Fig. 5, RJ-B), the tandem PCEs were limited by parasitic absorption in the hole-collecting top contact of the perovskite sub-cell (J SC o 17 mA cm À2 ) and the PCEs remained below 23%.…”