Researchers use high bandgap top perovskite cell for 28.9% efficient perovskite-silicon tandem cell

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.

Read the full story Posted: Nov 12,2023

Researchers develop a doping strategy to improve the practicality of all-perovskite tandem solar cells

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. 

Read the full story Posted: Nov 11,2023

Researchers develop hydrogen-bonding-facilitated dimethylammonium extraction strategy for improved perovskite solar cells

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.

Read the full story Posted: Nov 10,2023

Researchers develop a 'molecular bridge' strategy to improve the performance of perovskite solar cells

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.

Read the full story Posted: Nov 08,2023

Researchers use perovskite nanocrystals to design bio-inspired imaging sensors capable of “seeing” into the UV range

Researchers at Nanjing University and University of Illinois at Urbana-Champaign have drawn inspiration from the enhanced visual system of the Papilio xuthus butterfly, and developed an imaging sensor capable of “seeing” into the UV range inaccessible to human eyes. 

The design of the sensor uses stacked photodiodes and perovskite nanocrystals (PNCs) capable of imaging different wavelengths in the UV range. Using the spectral signatures of biomedical markers, such as amino acids, this new imaging technology is even capable of differentiating between cancer cells and normal cells with 99% confidence.

Read the full story Posted: Nov 05,2023

Team reports perovskite-based process to simplify manufacturing of solid-state lighting

Researchers at the University of Missouri and the University of Tulsa have described a process using 3D printing to simplify the manufacturing of stable lighting technology. The work comes on the heels of the Biden administration’s recent decision to enforce a long-delayed rule banning the sale of most traditional incandescent light bulbs.

The team leveraged 3D printing to create resin-perovskite color conversion layers. Using an affordable 3D printer, they mixed perovskite nanocrystals capable of emitting green, yellow and red light with a transparent ultraviolet resin. The combination resulted in a thin color conversion layer that transformed UV light into various colors and demonstrated a high level of stability. The researchers then stacked these layers onto a UV light-emitting diode chip, producing a natural white light.

Read the full story Posted: Nov 05,2023

Researchers report light guide plate based on perovskite nanocomposites

Perovskite nanocrystals (PNCs)/polymer nanocomposites can combine the advantages of both materials, but achieving the fabrication of PNCs/polymer nanocomposites by bulk polymerization has proven Very challenging. A team of scientists, led by Professor Bai Yang from Jilin University in China, has adopted a a two-type ligand strategy to fabricate bulk PNCs/polystyrene (PS) nanocomposites, including a new type of synthetic polymerizable ligand.

The CsPbCl3 PNCs/PS nanocomposites reportedly showed extremely high transparency that can be ascribed to the Rayleigh scattering as the PNCs distribute uniformly without obvious aggregation. Based on this behavior, the team first exploited the potential of PNCs to serve as scatters inside light guided plate (LGP), whose surface illuminance and uniformity can be improved, and this new kind of LGP is compatible with advanced liquid crystal display technology. 

Read the full story Posted: Nov 04,2023

Researchers develop method homogenizing perovskite films

An international team that included scientists from the Chinese Academy of Sciences (CAS), Southern University of Science and Technology (SUSTech), University of Science and Technology of China (USTC), Sungkyunkwan University (SKKU), The Hong Kong University of Science and Technology, University Grenoble-Alpes, CEA, CNRS, INP, IRIG/SyMMES, IEK5-Photovoltaics and North China Electric Power University (NCEPU), has proposed a new method of fabricating homogenized perovskite films for solar cells. 

The process involves inhibiting phase segregation caused by internal cation inhomogeneity to increase conversion efficiency to 26.1%, thus tying the existing record.

Read the full story Posted: Nov 03,2023

Researchers design commercially viable perovskite/CuInSe2 thin-film tandem solar cells with 29.9% efficiency

Researchers at Empa, National University of Singapore (NUS) and Helmholtz Institute Erlangen-Nürnberg for Renewable Energy HI ERN have reported novel electrical and optical enhancement approaches to maximize the performance of perovskite front cells. 

The team introduced new electrical and optical techniques, using methyldiammonium diiodide and adjusting the optical interference spectrum. This resulted in a record efficiency of 20.2% (21.8% by J-V scan) for a semi-transparent perovskite cell and 81.5% average near-infrared transmittance. 

Read the full story Posted: Nov 02,2023

Researchers examine a perovskite-graphene device for X-ray detection

Researchers at Graphenea, University of Utah and Kairos Sensors have examined a perovskite-based graphene field effect transistor (P-GFET) device for X-ray detection.

The device architecture consisted of a commercially available GFET-S20 chip, produced by Graphenea, with a layer of methylammonium lead iodide (MAPbI3) perovskite spin coated onto the top of it. This device was exposed to the field of a molybdenum target X-ray tube with beam settings between 20 and 60 kVp (X-ray tube voltage) and 30–300 μA (X-ray tube current). Dose measurements were taken with an ion-chamber and thermo-luminescent dosimeters and used to determine the sensitivity of the device as a function of the X-ray tube voltage and current, as well as source-drain voltage.

Read the full story Posted: Nov 01,2023