Efficiency - Page 26

Researchers from China's Nanjing University of Posts & Telecommunications, Sichuan University and Chinese Academy of Sciences (CAS) recently developed a new technology for the production of perovskite films that uses effects similar to those of facial masks, which promote the absorption of skincare products into the skin.

The newly developed technology made it possible to produce high-quality films with a smooth surface and a high efficiency of converting solar energy into electrical power.

Researchers from South Korea's Sungkyunkwan University (SKKU) have found that molybdenum ditelluride could increase carrier generation in perovskite solar cells.

They simulated a tandem solar cell with two absorbers based on methylammonium lead triiodide (CH₃NH₃PbI₃) – a perovskite with high photoluminescence quantum yield – and molybdenum ditelluride (MoTe₂), which is known for being naturally p-doped, with cascaded bandgaps to absorb a wider solar spectrum. The team determined that its efficiency could exceed 20%.

Scientists from the Centre for Solar Energy and Hydrogen Research Baden-Württemberg (ZSW) have achieved 21.1 percent efficiency with tandem perovskite - CIGS solar cells. These thin-film-based modules are highly efficient, light and flexible and can open doors to many new use cases for which standard rigid modules are not suitable.

ZSW’s tandem solar module has an area of nine square centimeters and achieves 21.1 percent efficiency. This prototype also features scalable component architecture suitable for industrial manufacturing. The best performance attained to date with tandem solar modules made of perovskite and CIGS is just slightly higher at 22 percent. ZSW has already achieved an excellent efficiency level of 26.6 percent with this combination of materials in smaller laboratory cells.

Researchers from Northwestern University, University of Toronto and the University of Toledo have developed an all-perovskite tandem solar cell with extremely high efficiency and "record-setting" voltage.

“Further improvements in the efficiency of solar cells are crucial for the ongoing decarbonization of our economy,” says U of T Engineering Professor Ted Sargent (ECE). “While silicon solar cells have undergone impressive advances in recent years, there are inherent limitations to their efficiency and cost, arising from material properties. Perovskite technology can overcome these limitations, but until now, it had performed below its full potential. Our latest study identifies a key reason for this and points a way forward.”

Researchers from the University of Surrey, Swansea University, University of Sheffield, University of Cambridge and University of Oxford in the UK, China-based CAS and Canada's University of Toronto have fabricated an inverted perovskite solar cell by using a surface modulator that reportedly facilitates superior passivation on perovskite surfaces, increasing overall cell efficiency. As the surface modulator, the scientists tested two organic halide salts known as 4-hydroxyphenethylammonium iodide (HO-PEAI), and 2-thiopheneethylammonium iodide (2-TEAI).

“These modulators can affect the surface energy of the perovskite films,” the team explained. They explained that the two compounds can dramatically reduce non-radiative interfacial recombination. This can have a significant impact on electrical performance in perovskite cells, with implications for open-circuit voltage, short-circuit current, fill factor, and ultimately, power conversion efficiency. They reported that “2-TEAI showed a stronger interaction than HO-PEAI, forming a quasi-2D structure on the perovskite surface without further annealing.”

Researchers from the National Center for Nanoscience and Technology (NCSNT) of the Chinese Academy of Sciences (CAS) and Beihang University have developed a sulfonium cations-assisted intermediate engineering strategy to study the evolution of intermediates and the film properties of quasi-2D perovskites. The researchers developed a facile strategy for intermediate engineering by employing sulfonium cations to regulate the transformation of intermediates during the crystallization process and improve the film quality of quasi-2D perovskites.

The intermediates were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM) to reveal the composition and transformation process of the intermediates. The introduction of sulfonium cations inhibited the formation of unfavorable solvated lead iodide and promoted the formation of favorable perovskite intermediates with fiber-like morphology, which is conducive to the formation of high-quality perovskite crystals. The above effects have been confirmed in quasi-2D perovskite with different n values and 3D perovskites.

Scientists from the Ural Federal University (UrFU) and the Institute of Organic Synthesis of the Ural Branch of the Russian Academy of Sciences (along with their colleagues) have proposed a new type of material for transporting electrons in perovskite solar cells, which has a number of advantages.

The team reported that with the new material, they were able to achieve solar energy conversion efficiency of 12%. "The family of molecules we found carries electrons in PSCs slightly worse than the fullerenes used today, but they are about twice as cheap, much easier to produce, and have a number of other technological advantages," says Gennady Rusinov, associate professor at the Department of Organic Synthesis Technology of UrFU.

Chinese perovskite solar technology company Renshine Solar (Suzhou) has announced achieving steady-state efficiency of 24.50% for all-perovskite tandem cell module, which it called 'a world record'.

It was reported that the efficiency was achieved for a perovskite module with an area of 20.25 cm², which exceeds that of perovskite single-junction components. The new efficiency level has been certified by Japan’s JET, it added without sharing other details.

Researchers from China's Huazhong University of Science and Technology and Singapore's National University of Singapore have introduced an eco-friendly and low-cost organic polymer, cellulose acetate butyrate (CAB), to the grain boundaries and surfaces of perovskites, resulting in a high-quality and low-defect perovskite film with a nearly tenfold improvement in carrier lifetime.

The CAB-treated perovskite films have a well-matched energy level with the charge transport layers, thus suppressing carrier nonradiative recombination and carrier accumulation. As a result, the optimized CAB-based device achieved a champion efficiency of 21.5% compared to the control device (18.2%).

Researchers from Helmholtz-Zentrum Berlin (HZB) and Potsdam University have reported perovskite–silicon tandem solar cells with periodic nanotextures that offer various advantages without compromising the material quality of solution-processed perovskite layers. Textured tandem devices have been presented before, aiming at improved optical performance, but optimizing film growth on surface-textured wafers has thus far remained challenging.

The research team showed a reduction in reflection losses in comparison to planar tandems, with the new devices being less sensitive to deviations from optimum layer thicknesses. The nanotextures also enabled a greatly increased fabrication yield from 50% to 95%. Moreover, the open-circuit voltage was improved by 15 mV due to the enhanced optoelectronic properties of the perovskite top cell. The optically advanced rear reflector with a dielectric buffer layer resulted in reduced parasitic absorption at near-infrared wavelengths. As a result, the team achieved a certified power conversion efficiency of 29.80%.