Perovskite applications - Page 5

Researchers from Duke University, University of Colorado - Boulder, Israel's Weizmann Institute of Science, Polish Academy of Sciences and University of Lille CNRS have examined the local structure of halide perovskites in their molten and glassy states, revealing the critical connection between these structures and the contrasting properties observed in their crystalline vs glassy states. 

The findings of this work enhance scientists' understanding of the diverse structural motifs in perovskites and how structural changes in perovskite glass impact their properties, paving the way for advancements in next-generation phase change materials and devices.

Researchers from China's Northwestern Polytechnical University, The Hong Kong University of Science and Technology, and Spain's Technical University of Madrid have developed a new lithium-free doping strategy to fabricate spiro-OMeTAD-based hole transport layers (HTLs) for applications in perovskite solar cell. A PV device built with a lithium salt-doped HTL achieved an efficiency of 25.45%.

Schematic illustration of a n-i-p PSC with spiro-OMeTAD HTLs doped by LiTFSI or Eu(TFSI)₂. Image from Nature Communications

The team's lithium-free doping strategy to fabricate a perovskite solar cell is based on a metal-free hole transport layer (HTL) made of spiro-OMeTAd that reportedly offers remarkable efficiency and stability levels. The research team explained that spiro-OMeTAD for perovskite cell applications is usually doped with a compound known as lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) to enhance hole extraction and conductivity. This kind of doping, however, requires time-intensive air-oxidization for 24 hours, which reportedly represents an obstacle to the commercial production of perovskite PV devices.

An NSW Smart Sensing Network Grand Challenge Fund project is hoping to eliminate the reliance of sensors on disposable batteries by testing the fast production of perovskite photovoltaic (PV) cells, in the hope of creating a more sustainable sensor power source. The NSW Smart Sensing Network, a consortium of eight leading universities across NSW and the ACT, is a not-for-profit innovation network that brings together universities, industry and government to translate world-class research into innovative smart sensing solutions that create value for NSW and beyond.

The Revolutionizing Indoor Sensor Power: Rapid Microwave Annealing for Ultra-low-cost Perovskite Solar Cells project is being led by Dr. Binesh Veettil, a Senior Lecturer in the School of Engineering at Macquarie University. “Perovskite cells offer continuous power, and are ideal for harvesting indoor light to power low-power sensors,” Dr. Veettil says. “They are cost-effective when mass manufactured and they are suitable for roll-to-roll manufacturing as they can be screen-printed, slot-die coated, or spray-painted. Unfortunately the lengthy annealing time required is a challenge to be addressed to enable their widespread adoption.”

Researchers from CHOSE (Centre for Hybrid and Organic Solar Energy) at Tor Vergata University of Rome, ENEA Frascati Research Centre, Fraunhofer FEP, University of Guilan and Halocell Europe have developed perovskite solar cells (PSCs) on polycarbonate films.

Despite polycarbonate's widespread use in many applications, poor chemical resistance and roughness have hindered its adoption as a substrate in solar cell technologies. These challenges were solved by developing a new planarizing layer over the polycarbonate films applied in liquid form using blade coating. This innovation reduced surface roughness from 1.46 µm to 23 nm, cut the water vapor transmission rate in half, and improved solvent resistance. As a result, the scientists achieved a power conversion efficiency of 13.0% for solar cells on polycarbonate substrates, with good durability and flexibility.

A team of researchers, led by Professor David Di from the International College of Zhejiang University and the School of Optoelectronic Science and Engineering, recently achieved a continuous transition from n-type to p-type perovskite semiconductors through molecular doping, while maintaining extremely high luminescence performance. 

Image credit: Zhejiang University

Based on controllable doping, the team developed a perovskite LED with a simple structure and reported a record for the highest brightness of solution-based LEDs, reaching 1.16 million nits.

Researchers from Korea's Ulsan National Institute of Science and Technology (UNIST) have addressed critical challenges in perovskite solar cells (PSCs), significantly enhancing both their efficiency and stability. The team achieved precise control over ion arrangement and reduced structural irregularities by incorporating a bidirectional coordinator between the perovskite photoactive layer and the electron transport layer.

Image credit: UNIST

The research team introduced trifluoroacetate (TFA-) ions between the perovskite layer and the tin oxide substrate, which serves as the electron transport layer (ETL), to mitigate defects.

Researchers from Ming Chi University of Technology, National Taiwan University of Science and Technology and Chang Gung University have explored the effect of self-assembled monolayers (SAMs), readily deposited via spin-coating, on defect passivation in sol–gel NiOx for perovskite solar cells (PSCs).

The team explained that while mixed-halide PSCs are highly attractive for indoor light-harvesting applications (thanks to their tunable bandgap and low-cost fabrication), achieving efficient carrier transport and defect passivation at the critical nickel oxide (NiOx)/perovskite interface, particularly under low light conditions, remains a challenge. Self-assembled monolayers (SAMs) offer a promising solution by introducing a tailored interface that promotes perovskite growth, suppresses non-radiative recombination, and facilitates efficient carrier transport. 

Researchers at the Nova University of Lisbon, University of Aveiro and University of York have created an ultra-thin perovskite solar cell with a checkerboard tile pattern that shields the perovskite layer from UV degradation. The design includes a luminescent down-shifting encapsulant, which enhances UV photon conversion and boosts overall efficiency.

The team provided background for this work, stating that advanced light management techniques can enhance the sunlight absorption of perovskite solar cells (PSCs). When located at the front, they may act as a UV barrier, which is paramount for protecting the perovskite layer against UV-enabled degradation. Although it was recently shown that photonic structures such as Escher-like patterns could approach the theoretical Lambertian-limit of light trapping, it remains challenging to also implement UV protection properties for these diffractive structures while maintaining broadband absorption gains. 

Researchers from China's Hebei University of Technology have developed a scalable method combining physical thermal field and chemical bonding to fabricate inch-sized FAPbI₃ wafers. By integrating 120 °C hot-pressing to stabilize the photoactive α phase and polyaniline polymer to conduct and passivate the grain boundaries, the team obtained quasi-single crystal FAPbI₃ wafers on a large scale. 

This approach reportedly overcomes the critical challenges of phase impurities and high-density defects, enhancing the phase stability of the FAPbI₃ wafers. 

Reports suggest that a solar power project in China, which utilizes translucent perovskite panels, has recently been connected to the grid in Gansu Province. This project was developed through a collaboration between the Electric Power Science Research Institute of the China State Grid Gansu Electric Power Company and a renewable energy subsidiary of China Datang Corp.

It was stated that the perovskite solar cells were processed to be translucent by the application of special graphical structures, including grind lines and dots, on the perovskite film. The specific structures are the result of precise control of parameters, including exposure time and depth. The graphical structures allow for the optimization of the light propagation path within the cell, thereby enhancing light absorption efficiency and improving the cell’s photoelectric conversion performance.