Researchers at Nanjing University in China and the University of Toronto in Canada have fabricated all-perovskite tandem solar cells (PSCs) with remarkable independently certified PCEs of 24.8% for small-area devices (0.049 cm²) and 22.1% for large-area devices (1.05 cm²).

Fabricating all-perovskite tandem solar cells, based on both wide-bandgap and narrow-bandgap perovskites, could lead to a higher power conversion efficiency (PCEs) than that attained by single-junction cells without increasing fabrication costs. In order to build this new type of solar cell, however, researchers need to find a way to enhance the performance of each subcell, while also integrating the wide-bandgap and narrow-bandgap cells synergistically.

An HZB team has successfully raised funds from the 'Helmholtz European Partnering Program' of the Helmholtz Association to expand cooperation with partners of the University of Ljubljana, Slovenia. The topics of the cooperation are tandem solar cells made of perovskite and silicon and, in particular, their precise characterization.

The TAPAS project is funded by the Helmholtz European Partnering programme for the next three years with 250,000 euros per year each. Following an evaluation, the funding period can be extended by two years. The Helmholtz European Partnering programme was set up to strengthen the European research area, in particular cooperation with countries in Southern, Central and Eastern Europe.

A group of scientists from ITMO University in Russia has proposed a new method for quick cooling-down of surfaces using perovskite and light nanoparticles. This principle may be used to cool nano-lasers in optical chips, increase the lifetime of solar panels, and create smart glass.

The ITMO team, which has been conducting research into the creation of optoelectronic devices and ultra-compact lasers based on perovskites, has decided to make use of light, which is normally the agent that creates the heating-up effect putting the material in danger.

Scientists from UCL and ISIS have been testing solar cells made from perovskite materials to see how resilient they are to the neutron irradiation they would be exposed to in space.

Solar cells made from perovskite materials have the potential for use in powering electronics in space. Before considering them for space applications, it is crucial to understand how resilient they would be in such a high radiation environment. In previous experiments by other groups, the effect of high-energy protons and electrons has been tested, with the results suggesting that this type of solar cell is particularly resilient to radiation effects. This experiment, on VESUVIO at ISIS, is the first to test cells in operando while being exposed to high-energy neutrons, and found that the cells suffered minimal irreversible damage during the process.

Researchers at the Indian Institute of Science Education and Research (IISER) Pune have converted perovskite into a highly stable photocatalyst, capable of decomposing toxic organic pollutants commonly present in water. The catalyst that becomes active when exposed to sunlight was synthesized by encapsulating nanocrystals of organic-inorganic perovskite inside a metal-organic framework (MOF).

The team led by Sujit K. Ghosh utilized the hydrophobic nature of the MOF material to render greater chemical stability to perovskite nanocrystals that form inside the MOF cavities. The perovskite-MOF composites reportedly displayed 'outstanding' stability when immersed inside water and alcoholic solvents for as long as 90 days.

Chinese manufacturer GCL recently indicated that it is nearing commercialization of perovskite solar technology. 'Once the conversion rate [of] perovskite is close to what monocrystalline product does, which is coming soon, the only obstacle for perovskite to take [the] place of mono is the limitation of its production capacity,' GCL Nano Technology general manager Fan Bin said at a recent industry conference which considered the potential of perovskite.

Discussing GCL's work with perovskites, Fan said his company's lab has achieved a conversion efficiency of 16% on a large panel and he is confident 18% could be achieved by the end of the year. With a theoretical conversion limit of around 33% thought to apply to perovskite cell efficiency ' and possibly up to 47% for a tandem device ' the manager voiced confidence perovskites would soon surpass the 18% threshold.

Researchers from King Abdullah University of Science and Technology (KAUST) in Saudi Arabia and University of Twente in the Netherlands have developed transparent conductive films that let through a broader range of the solar spectrum, which are set to increase the power conversion efficiency of perovskite-based multijunction solar cells beyond 30%.

A comparison of the used device test structures with different silicon bottom cells. Image taken from Advanced Functional Materials

Performance of perovskite-based tandem solar cells rests on the ability of the top cell to harvest the blue portion of the solar spectrum while letting through the near-infrared light. Conversely, the bottom cell only needs to absorb near-infrared light. "The semitransparency of the top cell depends on the optical bandgap and thickness of the perovskite thin film as well as the characteristics of the transparent electrodes, especially their sun-exposed side," explains study lead Stefaan De Wolf from theKAUST Solar Center.