Solar Energy

A new modifier increases the efficiency of perovskite solar cells

Published

4 years ago

February 12, 2021

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A new modifier increases the efficiency of perovskite solar cells

The research team of NUST MISIS has presented an improved structure of perovskite solar cells. Scientists have modified perovskite-based solar cells using MXenes – thin two-dimensional titanium carbides with high electrical conductivity.

The MXenes-based modified cells showed superior performance, with power conversion efficiency exceeding 19% (the reference demonstrated 17%) and improved stabilized power output with respect to reference devices. The results have been published in the Nano energy international scientific journal.

Perovskite solar cells are promising alternative energy technology worldwide. They can be printed on special inkjet or slot die printers with minimal quantity of vacuum processes. This reduces the cost of the device compared to traditional silicon solar cell technology.

Their other advantages are flexibility (the solar cell can be made on substrates of PET a common material for plastic bottles) and compactness. Perovskite solar cells can be mounted on the walls of buildings and curved surfaces of automobile panoramic roofs, receiving independent power supply.

The perovskite module has a sandwich structure: there is a process of collecting electrons between the layers. As a result, the energy of sunlight is converted into electrical energy.

The layers are very thin – from 10 to 50 nanometers, and the “sandwich” itself is thinner than a human hair. The collection of the charge carriers in the solar cells should go with minimal losses during electron transport. The reduction of the such losses in the device will increase the power of the solar cell.

A scientific group of physicists from NUST MISIS and the University of Tor Vergata (Rome, Italy) have shown experimentally that the addition of a small amount of titanium carbide-based MXenes to light-absorbing perovskite layers improves the electronic transport process and optimizes the performance of the solar cell.

The name – MXenes comes from the synthesis process. The material is made by etching and exfoliation of the atomically thin metal carbides pre-coated with aluminum (MAX phases – layered hexagonal carbides and nitrides).

“”In this work, we demonstrate a useful role of MXenes doping both for the photoactive layer (perovskite) and for the electron transport layer (fullerenes) in the structure of solar cells based on nickel oxide,” said the co-author of the paper, a researcher from the NUST MISIS Laboratory for Advanced Solar Energy, post-graduate student Anastasia Yakusheva.

“On the one hand, the addition of MXenes helps to align the energy levels at the perovskite/fullerene interface, and, on the other hand, it helps to control the concentration of defects in the thin-film device, and improves the collection of photocurrent.”

The solar cells developed with the new approach have shown improved characteristics with a power conversion efficiency exceeding 19%. This is 2% more in comparison to the reference devices.

The approach proposed by the developers can be easily scaled to the format of modules and large-area panels. Doping with MXenes does not change the fabrication sequence and integrated only to the initial stage of ink preparation without changes to architecture of the device.

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Solar Energy

Buried interface engineering drives advances in tin-lead perovskite solar cell efficiency

Published

2 days ago

December 20, 2024

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Buried interface engineering drives advances in tin-lead perovskite solar cell efficiency

by Simon Mansfield

Sydney, Australia (SPX) Dec 20, 2024

A team led by Prof. Meng Li from Henan University’s School of Nanoscience and Materials Engineering has unveiled an innovative approach to overcoming stability and efficiency challenges in tin-lead (Sn-Pb) perovskite solar cells. The researchers’ work focuses on optimizing the buried hole-selective interface using a specially designed self-assembled material, offering major implications for single-junction and tandem solar cell technologies.

Tin-lead perovskites are valued for their narrow bandgap properties, which position them as key materials for producing high-efficiency solar cells. However, energy level mismatches and degradation at the buried interface have constrained both their performance and long-term stability. Addressing these issues, Prof. Meng’s team designed a boronic acid-anchored hole-selective contact material, 4-(9H-carbazole-9-yl)phenylboronic acid (4PBA).

Compared to conventional materials, 4PBA demonstrated superior stability and compatibility at the substrate surface. Its high adsorption energy of -5.24 eV and significant molecular dipole moment (4.524 D) improved energy level alignment between the substrate and perovskite layer, facilitating efficient charge extraction. Additionally, the interface engineered using 4PBA improved perovskite crystallization and substrate contact, reducing defects and non-radiative recombination.

These advancements enabled Sn-Pb perovskite solar cells incorporating 4PBA to achieve a power conversion efficiency (PCE) of 23.45%. The material’s reduced corrosiveness also mitigated the degradation effects typically caused by PEDOT:PSS, a widely used hole-transport material, enhancing chemical stability and storage durability. The cells retained 93.5% of their initial efficiency after 2,000 hours of shelf storage.

“This approach offers a practical path to enhancing both the efficiency and stability of Sn-Pb perovskite solar cells, addressing energy level mismatches and interfacial stability concerns,” the research team commented.

The findings provide a foundation for advancing efficient and stable Sn-Pb perovskite solar cells and highlight the importance of interface engineering in next-generation photovoltaic technologies.

Research Report:Buried Hole-Selective Interface Engineering for High-Efficiency Tin-Lead Perovskite Solar Cells with Enhanced Interfacial Chemical Stability

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Solar Energy

New solar material advances green hydrogen production

Published

2 days ago

December 20, 2024

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New solar material advances green hydrogen production

by Simon Mansfield

Sydney, Australia (SPX) Dec 20, 2024

Researchers in nano-scale chemistry have made a significant stride in advancing the sustainable and efficient production of hydrogen from water using solar energy.

A collaborative international study led by Flinders University, with partners in South Australia, the US, and Germany, has identified a novel solar cell process that could play a crucial role in photocatalytic water splitting for green hydrogen production.

The research introduces a new class of kinetically stable ‘core and shell Sn(II)-perovskite’ oxide solar material. Paired with a catalyst developed by US researchers under Professor Paul Maggard, this material shows potential as a catalyst for the essential oxygen evolution reaction, a key step in generating pollution-free hydrogen energy.

The findings, published in The Journal of Physical Chemistry C, offer new insights into the development of carbon-free hydrogen technologies, leveraging renewable and greenhouse-gas-free power sources for high-performing and cost-effective electrolysis processes.

“This latest study is an important step forwards in understanding how these tin compounds can be stabilised and effective in water,” said Professor Gunther Andersson, lead author from the Flinders Institute for Nanoscale Science and Technology.

Professor Paul Maggard, from Baylor University, added, “Our reported material points to a novel chemical strategy for absorbing the broad energy range of sunlight and using it to drive fuel-producing reactions at its surfaces.”

Tin and oxygen compounds like those used in the study are already applied in diverse fields such as catalysis, diagnostic imaging, and therapeutic drugs. However, Sn(II) compounds are typically reactive with water and dioxygen, limiting their technological potential.

Global solar photovoltaic research continues to focus on developing cost-effective, high-performance perovskite-based systems as alternatives to conventional silicon and other existing technologies.

Hydrogen, often touted as a clean fuel, can be produced through various processes, including electrolysis powered by renewable energy, thermochemical water splitting using concentrated solar power, or waste heat from nuclear reactors. While fossil fuels and biomass can also generate hydrogen, the environmental and energy efficiency depends largely on the production method.

Solar-driven hydrogen production, which uses light to initiate the process, is emerging as a promising alternative for industrial-scale hydrogen generation.

This study builds on earlier research led by Professor Maggard, initially at North Carolina State University and now at Baylor University, and includes contributions from University of Adelaide experts such as Professor Greg Metha and collaborators from Universitat Munster in Germany. Professor Metha’s work explores the photocatalytic activity of metal clusters on oxide surfaces for reactor technologies.

Research Report:Chemical and Valence Electron Structure of the Core and Shell of Sn(II)-Perovskite Oxide Nanoshells

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Solar Energy

University of Houston scientists solving meteorological mysteries on Mars

Published

2 days ago

December 20, 2024

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University of Houston scientists solving meteorological mysteries on Mars

by Bryan Luhn for UH News

Houston TX (SPX) Dec 20, 2024

A groundbreaking achievement by scientists at the University of Houston is changing our understanding of climate and weather on Mars and providing critical insights into Earth’s atmospheric processes as well.

The study, led by Larry Guan, a graduate student in the Department of Physics at UH’s College of Natural Sciences and Mathematics, under the guidance of his advisors, Professor Liming Li from the Department of Physics and Professor Xun Jiang from the Department of Earth and Atmospheric Sciences and several world-renowned planetary scientists, generated the first-ever meridional profile of Mars’ radiant energy budget, or REB, which represents the balance or imbalance between absorbed solar energy and emitted thermal energy across the latitudes. On a global scale, an energy surplus leads to global warming, while a deficit results in global cooling. Furthermore, the meridional profile of Mars’ REB fundamentally influences weather and climate patterns on the red planet.

The findings are in a new paper just published in AGU Advances and will be featured in AGU’s prestigious science magazine EOS.

“The work in establishing Mars’ first meridional radiant energy budget profile is noteworthy,” Guan said. “Understanding Earth’s large-scale climate and atmospheric circulation relies heavily on REB profiles, so having one for Mars allows critical climatological comparisons and lays the groundwork for Martian meteorology.”

The profile, based on long-term observations from orbiting spacecraft, offers a detailed comparison of Mars’ REB to that of Earth, uncovering striking differences in the way each planet receives and radiates energy. While Earth exhibits an energy surplus in the tropics and a deficit in the polar regions, Mars displays the opposite configuration.

“On Earth, the tropical energy surplus drives warming and upward atmospheric motion, while the polar energy deficit causes cooling and downward atmospheric motion,” Jiang explained. “These atmospheric motions significantly influence weather and climate on our home planet. However, on Mars, we observe a polar energy surplus and a tropical energy deficit.”

That surplus, Guan says, is especially pronounced in Mars’ southern hemisphere during spring, playing a critical role in driving the planet’s atmospheric circulation and triggering global dust storms, the most prominent feature of Martian weather. These massive storms, which can envelop the entire planet, significantly alter the distribution of energy, providing a dynamic element that affects Mars’ weather patterns and climate.

“The interaction between dust storms and the REB, as well as with polar ice dynamics, brings to light the complex feedback processes that likely shape Martian weather patterns and long-term climate stability,” Guan said.

Earth’s global-scale energy imbalance has been recently discovered, which significantly contributes to global warming at a magnitude comparable to that caused by increasing greenhouse gases. Mars presents a distinct environment due to its thinner atmosphere and lack of anthropogenic effects. The research team is now examining potential long-term energy imbalances on Mars and their implications for the planet’s climate evolution.

“The REB difference between the two planets is truly fascinating, so continued monitoring will deepen our understanding of Mars’ climate dynamics,” Li said. “This research not only deepens our knowledge of the red planet but also provides critical insights into planetary atmospheric processes.”

Research Report:Distinct Energy Budgets of Mars and Earth