Innovation - TandPerovskite Solar Modules

Innovation – Tandem All-Perovskite Solar Modules With 19.1% Efficiency

Karlsruhe Institute of Technology (KIT) researchers have created a prototype for completely scalable all-perovskite tandem solar panels. With an aperture area of 12.25 square centimeters, these modules offer an efficiency of up to 19.1 percent.

a, Schematic and layer stack of all-perovskite tandem solar cells applied in this work. The champion tandem solar cells and modules employ sputtered indium tin oxide layers (thickness ~15 nm) and percolated Au thin films (nominal thickness ~1–2 nm) as a recombination layer, respectively. NBG and WBG are the abbreviations of the narrow and wide bandgap. b, Current density–voltage (J–V) curve and power conversion efficiency tracked at the maximum power point of the champion tandem devices for 5 min (in the inset). c, EQE of top and bottom subcell as well as the sum of both (grey symbolled line), and total absorbance calculated by 1 − reflectance (black solid line) for monolithic all-perovskite tandem solar cells. The light and dark blue regions denote the parasitic absorption and reflection losses, respectively. The corresponding losses in current density are provided.

This discovery, the first of its kind recorded anywhere in the world, was made feasible by increasing efficiency through improved light routes, high-throughput laser scribing, and the utilization of proven industrial coating processes.

Tandem solar cells create more power and employ a larger spectrum, making them more efficient. Perovskite solar cells with configurable band gaps are attractive tandem partners for both other-material solar cells and all-perovskite tandem solar cells.

d, Schematic illustration of the two-terminal all-perovskite tandem solar module (not to scale) interconnection denoting the active area and scribing lines (for more details see Supplementary Fig. 21). The colour used for the module layers is the same as for tandem solar cells. e, J–V characteristics of individual tandem cell stripes of the module and the respective fill factors after a stepwise inclusion of cell stripes included in the measurement. f, Power, voltage and current at the maximum power point of the champion tandem solar module under continuous AM 1.5G illumination. g, Normalized power (Norm.), voltage and current at the maximum power point under temperature stress at 85 °C in nitrogen atmosphere. Panels ac refer to tandem solar cells while panels dg to tandem modules.

This astounding outcome is the consequence of three crucial advances. The KIT researchers improved the efficiency of the perovskite solar cell design by optimizing the light route and eliminating reflections. They used high-throughput laser scribing to design an efficient layout for tandem solar modules, allowing the fabrication of functioning tandem solar mini-modules with two-terminal linked cell strips. Finally, they employed well-established industrial coating procedures (blade coating and vacuum deposition).

This result will serve as impetus for future research in academia and industry to commercialize the innovative and sustainable technology of all-perovskite tandem solar modules through scaling and stability enhancements.

Reference- Journal Nature Energy, Karlsruhe Institute of Technology (KIT) Media Outreach, Futurism, CLean Technica