Perovskite solar cells, a promising energy technology, have achieved a remarkable milestone in efficiency. Researchers at Kaunas University of Technology (KTU) in Lithuania have pushed the boundaries of perovskite tandem solar cells, achieving an impressive power conversion efficiency of over 29%. This breakthrough is a result of a simple yet innovative modification to the ultra-thin molecular layer responsible for charge carrier transfer within the device.
The key to this success lies in the creation of a more stable interface between the different layers of the solar cells. By altering the molecular group that bonds with the metal oxide layer, the researchers transformed it into an ionic salt. This change in molecular form has significant implications for the performance and longevity of the solar cells.
Kasparas Rakštys, a PhD researcher at KTU, explains that the new approach offers several advantages. The neutralized molecules create a non-aggressive interface, allowing the solar cell to operate more efficiently and stably. This is particularly important because the original acidic molecules could corrode adjacent layers, leading to defects and reduced efficiency over time.
The modified layer, only a few nanometers thick, has a substantial impact on charge transport. It binds strongly to metal oxide surfaces and is water-soluble, eliminating the need for toxic solvents during deposition. This makes the process more environmentally friendly and potentially more scalable for industrial applications.
To validate their findings, the researchers collaborated with partners in China, demonstrating the effectiveness of the new approach on large-area modules. The resulting high-quality coating is suitable for further practical testing, bringing us closer to the realization of versatile solar devices.
Perovskite tandem solar cells, which use multiple light-absorbing layers to capture a broader spectrum of sunlight, have seen significant improvements. The KTU team's achievement of over 29% efficiency in these cells is one of the highest reported values to date. This opens up exciting possibilities for the future of solar technology, including the integration of solar cells into building facades, windows, and textiles.
The researchers have already filed a patent for their innovation and are actively working towards its commercial implementation. This development is a significant step forward in the field of renewable energy, offering a more efficient and sustainable solution for power generation.
