Perovskite Solar - Page 25

Researchers at the University of Victoria in Canada and Solaires Enterprises have designed a flexible perovskite solar cell with an active area of 0.049 cm² based on a polyethylene terephthalate (PET) substrate and a reactant known as phenyltrimethylammonium chloride (PTACl) in ambient air fabrication.  Tested under standard illumination conditions, the flexible perovskite device achieved a power conversion efficiency of 17.6%, an open-circuit voltage of 0.95 V, a short-circuit current density of 23 mA cm⁻², and a fill factor of 80%.

The team explained that PET is cheaper than commonly utilized polyethylene naphthalate (PEN) in substrates for flexible solar cells, with the latter having however the advantage of being more thermally stable during the production process. PET, by contrast, has a maximum temperature tolerance of 100 C and can tolerate deposition procedures under this threshold. For this reason, the research group chose a cell architecture with a substrate made of PET and indium tin oxide (ITO), an electron transport layer (ETL) based on tin oxide (SnO₂), a methylammonium lead iodide (MAPbI₃) perovskite absorber, a Spiro-OMeTAD hole-transporting layer (HTL), and a gold (Au) metal contact.

An international team of researchers from King Abdullah University of Science and Technology (KAUST), Ulsan National Institute of Science and Technology (UNIST) and the Chinese Academy of Sciences have reportedly developed an inverted perovskite solar cell incorporating low-dimensional perovskite layers at the solar cell's top and bottom interfaces. 

The team achieved optimal passivation in inverted perovskite solar cells by applying thin layers of low-dimensional perovskite on top of a 3D perovskite film. The resulting cell achieved an open-circuit voltage of 1.19 V, a short-circuit current density of 24.94 mA cm², and a fill factor of 85.9%.

Researchers from the Korea Institute of Energy Research (KIER), Korea Research Institute of Standards and Science, Jusung Engineering and the Jülich Research Center have reported an advancement in the stability and efficiency of semi-transparent perovskite solar cells.

The semi-transparent solar cells achieved an impressive efficiency of 21.68%, which is said to be the highest efficiency to date among perovskite solar cells that use transparent electrodes. Additionally, they showed remarkable durability, with over 99% of their initial efficiency maintained after 240 hours of operation.

Researchers at the Karlsruhe Institute of Technology (KIT), Institute for Solar Energy Research Hamelin (ISFH) and Leibniz University Hannover have designed triple-junction perovskite–perovskite–silicon solar cells with a record power conversion efficiency of 24.4%. 

Schematic of the solar cell. Image from Energy & Environmental Science

Optimizing the light management of each perovskite sub-cell (∼1.84 and ∼1.52 eV for top and middle cells, respectively), the team maximized the current generation up to 11.6 mA cm⁻². Key to this achievement was the development of a high-performance middle perovskite sub-cell, employing a stable pure-α-phase high-quality formamidinium lead iodide perovskite thin film (free of wrinkles, cracks, and pinholes). This enabled a high open-circuit voltage of 2.84 V in a triple junction. Non-encapsulated triple-junction devices retain up to 96.6% of their initial efficiency if stored in the dark at 85 °C for 1081 h.

Lead-halide perovskites hold great promise as the next generation of PVs, but unstable lead exposure through gas, water, and soil accumulation could have detrimental consequences if not properly controlled and recycled as perovskite use expands globally. There are also stability issues limiting operational lifetime for lead-perovskite devices themselves. Researchers have attempted to replace lead with slightly less toxic tin, but thus far tin-based perovskites still suffer from air instability. Without breakthroughs in stability and environmental safety, scaling perovskite solar technology could flood our waste stream with hazardous materials. Now, researchers from CHOSE (Centre for Hybrid and Organic Solar Energy) at the University of Rome Tor Vergata have addressed the concerns regarding toxicity and recyclability associated with the lead contained in perovskite solar cells. 

Image credit: ACS Energy Letters 

The scientists may have found a solution in a new lead-free antimony-based perovskite solar cell design. Their recent research demonstrates a mixed-cation perovskite-inspired material (PIM) that boosted efficiency by 81% compared to conventional cesium-only antimony solar cells, while also exhibiting unmatched stability.

Researchers at the University of North Carolina at Chapel Hill and CubicPV have developed mini solar modules based on perovskite cells treated with zinc trifluoromethane sulfonate [Zn(OOSCF₃)₂]. The scientists found that using a small amount of this zinc salt in the perovskite solution can address the issue of interstitial iodides, which are the most critical type of defects in perovskite solar cells that limits efficiency and stability. The zinc salt helps control the iodide defects in resultant perovskites ink and films. 

The scientists explained that this is a low-cost material that is used as an additive at a very small percentage in perovskite inks and that its use makes perovskite module fabrication more reproducible, which helps to also make it cheaper.

Tata Chemicals has announced a collaboration with IITB-Monash Research Academy for pioneering research in the field of perovskite/clean energy. The strategic partnership will aim to advance sustainable energy transition solutions and foster innovation in clean energy technologies.

Under this agreement, Tata Chemicals will support the next-generation technology research led by the IITB-Monash Research Academy focused on the transformative potential of perovskite materials in the field of clean energy.

U.S-based University of Vermont spinoff, Verde Technologies, has reported progress with its thin film coating technology in a pilot with contract manufacturer Verico Technology, demonstrating that its coating processes are transferable to existing commercial roll-to-roll manufacturing lines.

The companies completed the deposition of perovskite solution on a flexible substrate measuring 76.2 cm x 6,096 cm using standard manufacturing processes, equipment, and environmental conditions. The novel coating tool and process received the name Verde Slot Coating.

The Dutch government has drafted a public proposal to support the production of heterojunction and perovskite-silicon tandem modules, as well as building- and vehicle-integrated PV panels, with a maximum allocation of €70 million ($75.1 million) per solar manufacturing project. Rijksdienst voor Ondernemend Nederland (RVO), the state-run agency that manages the SDE++ program for renewable energy in the Netherlands, has publicly proposed the idea of supporting the production of solar panels, storage systems and electrolyzers. The new incentive scheme, “Investeringssubsidie maakindustrie klimaatneutrale economie” (IMKE), will fund a portion of the capital expenditure needed to build factories for the three clean energy technologies.

The RVO said that the incentives for the production of PV panels will be limited to products for building-integrated (BIPV) and vehicle-integrated (VIPV) applications, as well as heterojunction modules or perovskite-silicon tandem panels.

Researchers from Japan's National Institute for Materials Science (NIMS) and Hokkaido University have designed an inverted “n-i-p” perovskite solar cell with a new bond/charge regulated defect passivation technique, enabled by introducing bifunctional molecules onto the perovskite absorber. The device exhibited a low open circuit voltage deficit and impressive stability.

The newly-fabricated solar cell with was based on a perovskite material that doesn't contain methylammonium (MA) molecules. These molecules have intrinsic thermal instability and contribute to increasing the typical thermal instability of perovskite PV devices.