Researchers achieve 18.4% efficiency for 4T flexible perovskite-CIGS tandem mini-module
Researchers from Switzerland's Federal Laboratories for Materials Science and Technology (EMPA) and École Polytechnique Fédérale de Lausanne (EPFL) have designed a four-terminal tandem mini-module based on perovskite and copper, indium, gallium and selenium (CIGS) with an aperture area of around 2 cm2, and a geometric fill factor of over 93%.
Processing sequence of flexible NIR-transparent perovskite mini-module. Image from RRL Solar
The team reports that the key to efficient flexible perovskite-CIGS tandem modules is the development of near-infrared (NIR) transparent perovskite solar modules on a flexible polymer foil. To achieve these results, the researchers had to overcome the challenges of laser patterning on flexible substrates to realize the first all-laser scribed monolithically interconnected NIR-transparent perovskite mini-modules on polymer film. The perovskite mini-module used in the tandem panel was fabricated on a flexible polyethylene napthalathe (PEN) substrate mounted to a glass substrate in a p–i–n device architecture. This configuration, according to the research team, shows reduced absorption in the NIR region.
Researchers from EPFL and CSEM achieve 31.25% efficiency for tandem perovskite-silicon solar cell
Researchers from the Swiss Center for Electronics and Microtechnology (CSEM) and the École polytechnique fédérale de Lausanne (EPFL) have reported a power conversion efficiency exceeding 30% for a 1 cm2 tandem perovskite-silicon solar cell, which represents a world record for a PV device of this kind. The team achieved an efficiency of 30.93% for a 1 cm2 solar cell based on high-quality perovskite layers from solution on a planarized silicon surface and an efficiency of 31.25% on a cell of the same size and fabricated with a hybrid vapor/solution processing technique compatible with a textured silicon surface.
“These results constitute two new world records: one for the planar and one for the textured device architecture,” the researchers explained, noting that both efficiencies were certified by the US Department of Energy's National Renewable Energy Laboratory (NREL). “The latter approach provides a higher current and is compatible with the structure of current industrial silicon solar cells”. Unfortunately, the researchers did not disclose technical details on how they improved the efficiency of both devices.
Researchers use a 2D perovskite passivation layer as an electron blocking layer in 18.5%-efficient carbon-electrode perovskite solar cell
Researchers from Fraunhofer Institute for Solar Energy Systems ISE, EPFL, Korea Basic Science Institute (KBSI) and Morocco's Abdelmalek Essaadi University have developed a perovskite solar cell with a carbon electrode that achieved 18.5% efficiency.
Schematic diagram of the investigated low-temperature carbon electrode-based PSC with 3D/2D perovskite treated by OAI. Image from study
The solar cell also reportedly retained 82% of their efficiency after 500 hours of continuous illumination. The cell is produced via all low-temperature processes that could likely be scaled into low-cost, large-scale manufacturing ' making the approach attractive despite achieving lower efficiency than record-setting cells.
EPFL team develops tandem solar cells with 29.2% efficiency
EPFL scientists in Neuchâtel have reported a tandem solar cell that can deliver a certified efficiency of 29.2%. This achievement was made possible by combining a perovskite solar cell with a textured silicon solar cell.
One obstacle the team encountered was finding a way to evenly coat the silicon surface'which is intentionally rough, or textured'with a thin film of halide perovskites. A textured surface is used in order to minimize light reflection. This kind of system can already be found in all commercially available crystalline silicon cells.
Researchers design ionic liquid-based perovskite solar cell with 22.86% efficiency
Researchers from EPFL, Tianjin University, Nanjing Tech University, The University of Tokyo, Shanghai University and Toyota Motor Corporation have used ionic liquids (ILs) with halide anions as additives to improve the performance and stability of a perovskite solar cell.
Image from study in Cell Reports Physical Science
Ionic liquids are viewed as a "greener" alternative to organic solvents due to their lower volatility and flammability, as well as to their wide liquid-state window.
