Efficiency - Page 25

A team of researchers, led by Professor Michael Grätzel at EPFL and Xiong Li at the Michael Grätzel Center for Mesoscopic Solar Cells in Wuhan (China), have developed a technique that addresses stability concerns of perovskite solar cells (PSCs) and increases their efficiency.

The researchers introduced a phosphonic acid-functionalized fullerene derivative into the charge-transporting layer of the PSC as a “grain boundary modulator”, which helps strengthen the perovskite crystal structure and increases the PSC’s resistance to environmental stressors like heat and moisture.

Scientists from Saudi Arabia’s King Abdullah University of Science and Technology (KAUST), Deutsches Elektronen-Synchrotron DESY, Academy of Sciences of the Czech Republic and Slovak Academy of Sciences have demonstrated a power conversion efficiency of 28.1% for a perovskite-silicon tandem solar cell based on textured silicon wafers.

Textured silicon wafers used in silicon solar cell manufacturing offer superior light trapping, which is a critical enabler for high-performance photovoltaics. The team explained that a similar optical benefit can be obtained in monolithic perovskite/silicon tandem solar cells, enhancing the current output of the silicon bottom cell. Yet, such complex silicon surfaces may affect the structural and optoelectronic properties of the overlying perovskite films.

Chinese perovskite solar technology company Renshine Solar (Suzhou) has announced 29.0% steady-state power conversion efficiency of all-perovskite tandem solar cell developed in-house. The company now expects to exceed 30% in 2023.

Japan Electrical Safety and Environment Technology Laboratories (JET) has reportedly certified the efficiency claim that was reported for a designated area of 0.04888 cm².

A team of researchers at EPFL have developed a method that improves both power conversion efficiency and stability of solar cells based on pure iodide as well as mixed-halide perovskites. The new method aslo suppresses halide phase segregation in the perovskite material. The research was carried out by the groups of Professors Michael Grätzel and Ursula Rothlisberger at EPFL and led by Dr Essa A. Alharbi and Dr Lukas Pfeifer.

The method treats perovskite solar cells with two alkylammonium halide modulators that work synergistically to improve solar cell performance. The modulators were used as passivators, compounds used to mitigate defects in perovskites, which are otherwise promoting the aforementioned degradation pathways.

Researchers at the National Renewable Energy Laboratory (NREL) and University of Toledo have developed a new approach to manufacturing perovskite solar cells.

Developing highly stable and efficient perovskites based on a rich mixture of bromine and iodine is considered critical for the creation of tandem solar cells. However, issues with the two elements separating under solar cell operational conditions, such as light and heat, limit the device voltage and operational stability. This challenge is often made worse by the ready defect formation associated with the rapid crystallization of bromine-rich perovskite chemistry with antisolvent processes.

Researchers from Monash University, Wuhan University of Technology, CSIRO Manufacturing, The Melbourne Centre for Nanofabrication and Foshan Xianhu Laboratory of the Advanced Energy Science and Technology Guangdong Laboratory have demonstrated "the first effective use of lead acetate as a precursor in making formamidinium-caesium perovskite solar cells". This could lead to a new way of creating durable, efficient perovskite photovoltaics at industrial scale.

Members of Exciton Science, based at Monash University, were able to create perovskite solar cells with 21% efficiency, which they say are the best results ever recorded for a device made from a non-halide lead source.

Researchers from Saule Research Institute, Saule Technologies, Centre for Hybrid and Organic Solar Energy (CHOSE), CNR-SCITEC, Istituto Italiano di Tecnologia (IIT), Wroclaw University of Science and Technology, Bydgoszcz University of Science and Technology and Poznan University of Technology have demonstrated an effective strategy to improve the technical aspects of flexible perovskite solar cells,  improving the reliability and efficiency values of these devices.

The team applies large organic ammonium molecules for modifying a buried interface between a hole-transporting layer (HTL) and perovskite-absorbing material. With the 4-fluorophenethylammonium iodide (FPEAI), they achieved 18.66% efficiency for the large-area (1 cm²) flexible solar cell, a significant improvement over the pristine device without modification.

Researchers at Helmholtz-Zentrum Berlin (HZB) recently announced a new tandem solar cell that converts 32.5% of the incident solar radiation into electrical energy.

The certifying institute European Solar Test Installation (ESTI) in Italy measured the tandem cell and officially confirmed this value which is also included in the NREL chart of solar cell technologies, maintained by the National Renewable Energy Lab, USA.

Meyer Burger Technology has signed multi-year cooperation agreements with CSEM from Switzerland, Helmholtz-Zentrum Berlin (HZB), the Fraunhofer Institute for Solar Energy Systems ISE in Freiburg, and the Institute of Photovoltaics at the University of Stuttgart, for the development of high-performance perovskite tandem solar cells and modules.

These activities are focused on the industrialization of the new technologies, moving from the laboratory to mass production with a view to the future expansion of gigawatt capacities at Meyer Burger’s production sites. The aim of the cooperation is the industrial production of solar cells with efficiencies of more than 30 percent.

Researchers from China's East China Normal University (ECNU), Shanghai University, Donghua University and Soochow University have fabricated an inverted perovskite solar cell with remarkable charge transport.

They reportedly suppressed carrier recombination at the interface between the perovskite and the charge transport layer, as well as defect-assisted recombination originating from the perovskite layer. The cell has a p-i-n structure, which means the perovskite cell material is deposited onto the hole transport layer, and then coated with the electron transport layer, unlike with conventional n-i-p device architecture. Inverted perovskite solar cells typically show strong stability, but lag behind conventional devices in terms of conversion efficiency and cell performance.