The Perovskite-Info newsletter (April 26, 2022)

A research team, co-led by scientists from City University of Hong Kong (CityU) and Imperial College London, has developed highly efficient and stable perovskite solar cells.

Among the different types of perovskite solar cells, those with an inverted design configuration have exhibited exceptional stability, making them good candidates to reach the lifetime of commercial silicon solar cells. However, perovskite materials include chemically reactive components, which can easily volatilize and degrade under high temperature and humidity, shortening the solar cells’ operational lifetime. Also, there is still a need for strategy to enhance the efficiency of inverted perovskite solar cells up to 25% to rival that of silicon solar cells, while maintaining their stability.

Tandem PV, a California-based photovoltaic technology company specializing in ultra-high-efficiency tandem metal-halide perovskite solar panels, has announced closing the initial $6 million of its $12 million Series A financing round. Tandem PV will use the funds to build a pilot manufacturing facility in San Jose, California.

The round was led by Bioeconomy Capital, an early-stage venture capital firm, through its new Planetary Technologies fund, with participation from an international solar manufacturer and a U.S. utility company.

A team of scientists, led by Mohammad Nazeeruddin at École polytechnique fédérale de Lausanne (EPFL), has found a way to address the scaling up challenges of perovskites. The scientists have developed an easy solvothermal method to produce single-crystalline titanium dioxide rhombohedral nanoparticles that can be used to build a perovskite film.

The new structure is said to feature a lower amount of lattice mismatches, referring to the "ladder-like" structure of the titanium dioxide nanoparticles. This translates into a lower number of defects, which ensures better electron flow throughout with lower power loss.

The Centre for Solar Energy and Hydrogen Research Baden-Württemberg (ZSW), aiming to fast-track tandem solar technology’s time to market, has put two new high-performance coating plants into operation.

The systems produce tandem solar cells consisting of a perovskite solar cell that can be combined with other types of solar cells. The various layers are deposited under ultra-clean conditions. Companies in the solar sector can take advantage of these capabilities to optimize their developments in the area of tandem solar cells.

KAUST researchers have shared a detailed view of how electrical charges behave inside perovskites, which could guide efforts to improve the performance of next-generation solar cells based on these materials.

When light hits a perovskite, it excites negatively charged electrons and leaves behind positively-charged “holes” within the material’s crystalline structure. These electrons and holes can then move through the perovskite to generate an electrical current. But the charge carriers could also recombine instead, which wastes the energy they carry.

A group of scientists from the University of Wuppertal, the University of Tübingen, the University of Potsdam, HZB, Max Planck Institute and the University of Cologne in Germany recently developed a perovskite-organic tandem solar cell with optimized charge extraction, a high open-circuit voltage and a thickness of just 1 µm.

The tandem configuration includes a narrow-bandgap organic subcell with a p-i-n-type architecture based on the polymer PM6 and molybdenum oxide (MoOx) as the hole extraction layer (HEL). The cell has a power conversion efficiency of 17.5%, an open-circuit voltage of 0.87 V, a short-circuit current of 26.7 mA cm−², and a fill factor of 75%. The wide-bandgap perovskite subcell was built with a perovskite known as FA_0.8Cs_0.2Pb(I_0.5Br _0.5)₃, with an efficiency of 16.8%, an open-circuit voltage of 1.34 V, a short-circuit current of 15.6 mA cm−², and a fill factor of 81%.

A collaborative research effort involving scientists from the US National Renewable Energy Laboratory (NREL) and other collaborators, has examined how well perovskite technology might work in the space, such as for powering satellites. The research group has presented guidelines to test the radiation-tolerating properties of perovskites intended for use in space.

“Radiation is not really a concern on Earth, but becomes increasingly intense as we move to higher and higher altitudes,” commented Ahmad Kirmani, a postdoctoral researcher at NREL and lead author of the new study.

Researchers from South Korea's Institute for Basic Science (IBS), Gwangju Institute of Science and Technology and Korea University have developed perovskite micro cells with a power conversion efficiency of 20.1% that can be used in colored solar windows.

the colored solar window with the metal–insulator–metal (MIM) resonant structure. The inset shows a cross-sectional view of the perovskite microcell in the colored solar window. Image from Nature Communications

The devices were built using a lift-off-based patterning approach based on swelling-induced crack propagation.

Researchers from South Korea's Institute for Basic Science (IBS), Gwangju Institute of Science and Technology and Korea University have developed perovskite micro cells with a power conversion efficiency of 20.1% that can be used in colored solar windows.

The colored solar window with metal–insulator–metal (MIM) resonant structure. The inset shows a cross-sectional view of the perovskite microcell in the colored solar window. Image from Nature Communications

The devices were built using a lift-off-based patterning approach based on swelling-induced crack propagation.