Technical / research - Page 38

Researchers from NREL, University of Wisconsin—Stout and Swift Solar have reported perovskite-based thermochromic windows that reduce energy load and carbon emission in buildings. The team calculated and fabricated a perovskite-based technology with excellent transition temperatures for building energy savings. 

The use of thermochromic windows in office buildings improves energy efficiency across all climate zones in the United States by modulating the temperature inside, leading to a massive savings, according to the research effort led by the U.S. Department of Energy’s National Renewable Energy Laboratory (NREL).

Researchers at University of Rome “Tor Vergata”'s CHOSE (Centre for Hybrid and Organic Solar Energy), Greatcell Italy, ISM-CNR and ENEA have studied a standard triple cation perovskite (∼1.58 eV) and wider bandgap perovskite (∼1.63 eV) with intention of finding a common strategy to build a robust device stable over time independently of the perovskite used.

The scientists used a combination of additives inside the perovskite ink: ionic liquid 1-Butyl-3 methylimidazolium tetrafluoroborate (BMIM-BF4), alkylamine ligands oleylamine (OAm) and benzylhydrazine hydrochloride (BHC). The recent work reveals that the combination of these additives helps to improve the efficiency and stability of the entire device, reaching a power conversion efficiency up to 21.3% and over 20% for both types of perovskite and stability beyond 1000 h under continuous light soaking.

Researchers from Georgia Institute of Technology, Argonne National Laboratory and Brookhaven National Laboratory have demonstrated that halide perovskite solar cells are less stable than previously thought. Their work reveals the thermal instability that happens within the cells’ interface layers, but also offers a path forward towards reliability and efficiency for halide perovskite solar technology.

The research could have significant implications for both academics and industry professionals working with perovskites in photovoltaics.

Researchers from Australia's Monash University, The Australian National University (ANU), Flinders University, The University of Sydney and Germany's Karlsruhe Institute of Technology have achieved a 30.3% efficiency with a perovskite and silicon tandem solar cell.

The team developed the highly efficient tandem cell, while also enhancing its operational stability. Their work builds on a previous record set by ANU researchers in 2020, and was funded by the Australian Renewable Energy Agency (ARENA).

Scientists at Rice University, INSA Rennes, SLAC National Accelerator Laboratory and Northwestern University have managed to directly visualize the structural dynamics in monocrystalline 2D perovskites. While researchers already knew the atoms in perovskites react to light, direct visualization of these reactions is considered a long-standing challenge. Now, it's been made possible to see precisely how those atoms move.

The team's study details the first direct measurement of structural dynamics under light-induced excitation in 2D perovskites. “The next frontier in light-to-energy conversion devices is harvesting hot carriers,” said Rice University’s Aditya Mohite, a corresponding author of the study. “Studies have shown that hot carriers in perovskite can live up to 10-100 times longer than in classical semiconductors. However, the mechanisms and design principles for the energy transfer and how they interact with the lattice are not understood.”

Researchers from Helmholtz-Zentrum Berlin (HZB), Chinese Academy of Sciences (CAS), Swansea University, University of Stuttgart, Henan University, University of Naples Federico II, Queen Mary University of London and Soochow University have investigated a chemical variation that significantly improves the stability of the perovskite thin film in different solar cell architectures, among them the p-i-n architecture.

Daily temperature variations induce phase transitions and lattice strains in halide perovskites, challenging their stability in solar cells. The international team in this work set out to address this issue and improve the stability of PSCs in the face of these changes. 

Researchers from the US Department of Energy’s National Renewable Energy Laboratory (NREL), University of North Texas and University of Oklahoma have demonstrated that an ultrathin layer of  silicon oxide layer can harden perovskite photovoltaics to protect it from critical stressors in space and on Earth. 

Space has its own unique environmental challenges for solar cells, perovskite ones included. PSCs have to be resilient against such challenges as “radiation, atomic oxygen, vacuum, and high-temperature operation,” according to the study’s abstract.

A research team from City University of Hong Kong (CityU), Curtin University, National Taiwan University, Huazhong University of Science and Technology, Nankai University and Polish Academy of Sciences recently developed a lead-free perovskite photocatalyst that delivers highly efficient solar energy-to-hydrogen conversion.

The team unveiled the interfacial dynamics of solid-solid (between halide perovskite molecules) and solid-liquid (between a halide perovskite and an electrolyte) interfaces during photoelectrochemical hydrogen production. The latest findings open up an avenue to develop a more efficient solar-driven method for producing hydrogen fuel in the future.

Researchers at the Research Institute of Sweden (RISE) and KTH Royal Institute of Technology have presented the ionic liquid (IL) synthesis of two novel pseudo-2D perovskite-type gold(III)polyiodide compounds and their use as active layers in monolithic solar cells.

The team stated that its recent work represents the first demonstration of film deposition of gold iodide/polyiodide compounds onto porous monolithic substrates with subsequent solar cell characterization. The devices reportedly showed promising photovoltaic performance and could unlock new materials design possibilities, ultimately moving away from lead-based photovoltaic materials. These findings further highlight the use of simple polyiodide entities to increase the structural and electronic dimensionality of gold perovskite-type anions.

Researchers at Switzerland's EPFL and Sungkyunkwan University in Korea have addressed the issue of perovskite solar cells' stability. They focused on the degradation of perovskite thin films, which can be damaged by exposure to moisture, heat, and light. The team looked at two specific crystal facets (the crystal's flat surface), characterized by a particular arrangement of atoms. The arrangement of atoms on these facets can affect the properties and behavior of the crystal, such as its stability and its response to external stimuli like moisture or heat.

The researchers looked at the (100) and (111) facets of perovskite crystals. The (100) facet is a plane that is perpendicular to a crystal's c-axis with its atoms arranged in a repeating pattern in the form of a square grid. In the (111) facet the atoms are arranged in a triangular grid. The study found that the (100) facet, which is most commonly found in perovskite thin films, is particularly prone to degradation as it can quickly transition to an unstable, inactive phase when exposed to moisture. In contrast, the (111) facet was found to much more stable and resistant to degradation.