Perovskite Solar - Page 32

Researchers at the Chinese Academy of Sciences (CAS), Peking University and  Soochow University have developed a polycrystalline silicon tunnelling recombination layer for perovskite/tunnel oxide passivating contact (TOPCon) silicon tandem solar cells (TSCs), which has reportedly achieved excellent efficiency and high stability.  

According to the team, previous efforts to increase device efficiency have mainly focused on improving the top sub-cell, leaving much room for improvement. The recombination layer, which serves as the electrical contact between the top and bottom sub-cells, plays a critical role in further efficiency progress. In this study, the researchers developed a polycrystalline silicon (poly-Si) tunnelling recombination layer that was incorporated into a perovskite/TOPCon silicon tandem cell. Through a two-step annealing strategy, the diffusion of boron and phosphorus dopants could be effectively restrained, granting the device excellent passivation and contact performance.

Tokyo Chemical Industry (TCI), a global supplier of laboratory chemicals and specialty materials, is offering a stable supply of high-quality Spiro-OMeTAD hole transport materials, used in perovskite solar panels, light emitting devices and other applications.

Spiro-OMeTAD materials are suitable for solution processing, and feature a HOMO of -5.0 eV and a LUMO of -1.5 eV. This is a standard material used in many perovskite stacks, and is the benchmark material also used in many research activities for comparative evaluation.

 TCI has a large-scale capacity to produce this material, in very high quality and at a relatively low cost. See here for more info. 

A new project, led by the University of Michigan, could enable industrial competitors to collectively build a predictive model that speeds the development of perovskite solar cells. The aim is to improve upon the process of layer-by-layer deposition of semiconductor materials during production with an information-sharing approach that boosts cooperation between companies while protecting proprietary information and worker interests.

The project is backed by a four-year, $3 million grant from the National Science Foundation and includes partners at the University of California San Diego.

Saule Technologies has announced that yesterday, November 11, the SpaceX Falcon-9 rocket with mission Transporter-9 was launched, carrying its perovskite cells to the Low Earth Orbit. 

photo credit: SpaceX and Saule Technologies

Saule Technologies stated that its team has put in immense work researching, developing and creating the perovskite-based PV module adapted for tests in space conditions. 

Researchers at Australia's University of Sydney, University of New South Wales, Macquarie University, Germany's Forschungszentrum Jülich, China's Southern University of Science and Technology ans Slovenia's University of Ljubljana have developed a perovskite-silicon solar cell design using a top perovskite PV device with an energy bandgap of 1.67 eV and a self-assembly monolayer based on carbazole. The tandem cell achieved a higher efficiency compared to counterparts without the monolayer and passed the IEC 61215 standard thermal cycling test.

The device is intended for applications as a top cell in perovskite-silicon tandem solar devices, where the upper cells must have a high energy bandgap to achieve output current matching. These top cells, however, suffer from a higher bandgap-voltage offset, due to non-radiative recombination and energetic misalignment between the perovskite and charge-selective layers. To address this issue, the team utilized a self-assembled monolayer (SAM) based on carbazole, which acts as an effective hole-selective layer (HSL). These SAMs were previously utilized in experimental solar cells and are commonly developed through a molecular glue added during processing in order to dramatically improve adhesion between the light-absorbing perovskite layer and the electron transport layer.

Researchers at China's Wuhan University assume that the practical use of all-perovskite tandem solar cells is hampered by the subpar performance and stability issues associated with mixed tin–lead (Sn–Pb) narrow-bandgap perovskite subcells. In their recent study, they focus on these narrow-bandgap subcells and develop an all-in-one doping strategy for them. 

The scientists introduce aspartate hydrochloride (AspCl) into both the bottom poly(3,4-ethylene dioxythiophene)–poly(styrene sulfonate) and bulk perovskite layers, followed by another AspCl posttreatment. They show that a single AspCl additive can effectively passivate defects, reduce Sn⁴⁺ impurities and shift the Fermi energy level. 

Researchers at the Chinese Academy of Sciences (CAS), Beijing Normal University, Beijing Institute of Technology and ShanghaiTech University have developed a universal hydrogen-bonding-facilitated DMA extraction method to fabricate high-quality γ-CsPbI3 films. The researchers fabricated a solar cell based on cesium-lead iodide (CsPbI₃) perovskite, which is also known as black perovskite.

The black perovskite solar cell reportedly achieved  20.25% efficiency, which is said by the team to be the highest efficiency reported for PV devices built with this perovskite material and a dopant-free hole transport layer based on the P3HT polymer. The cell was also able to retain around 93% of its original efficiency after continuous illumination for 570 h.

Researchers at China's Hefei Institutes of Physical Science (HIPS), University of Science and Technology of China (USTC), Southern University of Science and Technology (SUSTech), Hainan University, Germany's IEK5-Photovoltaics and University of Duisburg-Essen have proposed a strategy to enhance the performance of perovskite solar cells through the creation of a robust connection between different layers of the solar cell, using a molecular bridge made of ammonium cations.

The term 'fill factor' (FF) represents the capacity of a solar cell to deliver maximum current under optimal conditions. As limitations associated with FF still pose challenges, any advancements in this area are highly sought after. To address these limitations, the team focused on optimizing the bottom interface of the solar cell. They developed a strategy to redistribute localized electrostatic potential by employing ammonium cations as a molecular bridge with various degrees of substitution.

Reports suggest that BYD COMPANY aims to ramp up its R&D efforts in solar energy technologies, by setting up a team of professional researchers that will work on achieving cost reduction and efficiency enhancements.

With the advancement of crystalline silicon photovoltaic technology, BYD COMPANY is transitioning from PERC cell technology to N-type TOPCon and HJT cell technology, and has been actively exploring perovskite cell technology, with the aim to achieve higher conversion efficiency and stimulate technological innovations.

Reports suggest that LONGi Green Energy Technology managed to reach a conversion efficiency of 33.9% for its silicon-perovskite tandem solar cells.

The result, currently the highest efficiency record in the world for a perovskite/silicon tandem cell, has reportedly been confirmed by the US National Renewable Energy Laboratory (NREL).