Solar Energy

The perfect recipe for efficient perovskite solar cells

Published

4 years ago

February 24, 2021

sarosh

The perfect recipe for efficient perovskite solar cells

They have improved a process for vertically depositing a solution made from an inexpensive perovskite solute onto a moving substrate below. Not only have they discovered the crucial role played by one of the solvents used, but they have also taken a closer look at the aging and storage properties of the solution.

Solar cells made of crystalline silicon still account for the lion’s share of roof installations and solar farms. But other technologies have long since become established as well – such as those that convert sunlight into electrical energy through use of extremely thin layers of solar-cell material deposited upon a substrate. The perovskite solar cells that Prof. Eva Unger and her team at the Helmholtz-Zentrum Berlin (HZB) are researching belong to this group. “”These are the best solar cells to date that can be made using a 2D ink”, the researcher explains. “”And now their efficiencies are approaching those for cells made of crystalline silicon.””

Developing scalable methods

Many methods have been developed and used to fabricate small test cells in the laboratory, where they can be studied and improved. But industrial-scale fabrication is still a long way off. Unger knows from her own experience: “Unfortunately, processes that are optimised for fabricating small surface areas cannot always be scaled up.”

In other words: Not everything that works perfectly in the lab also necessarily works economically on the factory floor. “That’s why we are taking the next step and developing scalable methods. This means our team is focussing on processes for coating larger surfaces.” At the Hybrid Silicon Perovskite Research, Integration and Novel Technologies (HySPRINT) Innovation Lab, an infrastructure for collaboration between HZB and industry, the team is concentrating on processes that have already proven their importance in industry to start with.

“We have experimented here with slot-die coating”, she explains. In this process, the “ink”, as the thin liquid solution of perovskite precursor, solvent, and additive is known in the trade, flows from a slit-shaped nozzle and falls like a curtain onto the glass substrate being conveyed below that will later become a solar cell. After application, crystallisation begins. An ultra-thin layer of a semiconducting perovskite structure grows that gives the material group its name and the solar cell its capabilities.

Unger, together with her team members doctoral student Jinzhao Li and Dr. Janardan Dagar, have now discovered that the exact amount of an organic solvent called dimethyl sulfoxide (DMSO) in the material ink is critical for this process. Unger uses it as an additive because it has an amazing effect on the ink.

“”DMSO induces crystallisation nuclei for the perovskite”, says the researcher. Crystallisation nuclei usually are tiny grains that help jump-start a crystal and promote its growth. “”During X-ray diffraction experiments at BESSY II, we saw quite a big difference between inks with and without DMSO added”, the physical chemist explains.

It’s the amount that counts

However, as her team has found out in many experiments, the amount added plays a decisive role here. More DMSO favours crystal growth – up to a certain point. If this is exceeded, other processes come into play and the resulting microstructure reduces the performance of the solar cells. “It’s like seasoning a soup”, says Unger.

“If you add too little, it remains bland. If you add too much, it won’t taste good either. So you need to add just the right amount to make it best.” In addition to the optimal composition, the HZB team has also thoroughly investigated the ageing processes and thus the storage life of the inks. “This is an aspect that has received little attention so far”, Unger explains. “The age of a perovskite precursor ink can influence device performance. This is an important factor that must be considered when developing inks and processes.”

Source link

Solar Energy

China says wind and solar energy capacity exceeds thermal for first time

Published

7 hours ago

April 27, 2025

sarosh

China says wind and solar energy capacity exceeds thermal for first time

By Sam Davies and Luna Lin

Beijing (AFP) April 25, 2025

China’s wind and solar energy capacity has surpassed that of mostly coal-powered thermal for the first time, the national energy body said Friday.

China, the world’s largest emitter of greenhouse gases that drive climate change, has pledged to peak carbon emissions by 2030 and achieve carbon neutrality by 2060.

While around 60 percent of China’s energy comes from coal, the country is also a renewable energy powerhouse, building almost twice as much wind and solar capacity as every other country combined, according to research published last year.

“In the first quarter of 2025, China’s newly installed wind and photovoltaic power capacity totalled 74.33 million kilowatts, bringing the cumulative installed capacity to 1.482 billion kilowatts,” the national energy body said.

That surpassed the installed capacity of thermal power (1.451 billion kilowatts) for the first time.

President Xi Jinping said on Wednesday that “no matter how the international situation changes”, the country’s efforts to combat climate change “will not slow down”.

Xi also said China would announce its 2035 greenhouse gas reduction commitments, known as Nationally Determined Contributions (NDCs), before COP30 in November and that it would cover all greenhouse gases, not just carbon dioxide.

President Donald Trump meanwhile has pulled the United States, the world’s second-largest polluter, out of the Paris climate accord while pledging a vast expansion in fossil fuel exploitation.

-‘Structural change’-

China’s new milestone comes as the country experiences explosive growth in renewable energy.

Last year, China added a record 357 gigawatts of wind and solar, 10 times the US’s additions.

It met a 2030 target to install 1,200 GW of solar and wind capacity almost six years early.

Friday’s announcement said that wind and solar additions in the first quarter had “far exceeded” China’s total increase in electricity consumption.

“This trend is very likely to continue in the following months and quarters in 2025,” Yao Zhe, Global Policy adviser at Greenpeace East Asia, told AFP.

That suggests China’s power sector is undergoing “structural change and the sector’s carbon emissions are one small step away from peaking”.

However, coal continues to play a key role in China’s energy mix.

“The intermittency of variable renewables like wind and solar… means it’s generally inappropriate to compare them to firm, dispatchable power sources like coal,” according to David Fishman, senior manager at the Lantau Group.

“There is indeed some combination of wind plus solar plus storage that equals one coal plant, but the determination is different everywhere in the world.”

And China’s energy consumption continues to grow — by 4.3 percent last year.

Covering that growth with renewable power is a “tough proposition for a developing country with a huge heavy industrial segment and a residential population that frankly doesn’t even use that much electricity on a per capita basis”, Fishman said.

Despite the renewable energy boom, China also began construction on 94.5 gigawatts of coal power projects in 2024, 93 percent of the global total, according to a February report from the Finland-based Centre for Research on Energy and Clean Air (CREA) and Global Energy Monitor (GEM) in the United States.

China’s coal production has risen steadily in recent years, from 3.9 billion tons in 2020 to 4.8 billion tons in 2024.

That is despite Xi pledging to “strictly control” coal power before “phasing it down” between 2026 and 2030.

Source link

Solar Energy

A single molecule elevates solar module output and stability

Published

3 days ago

April 24, 2025

sarosh

A single molecule elevates solar module output and stability

by Sophie Jenkins

London, UK (SPX) Apr 24, 2025

A new molecule developed through international collaboration has been shown to significantly improve both the performance and durability of perovskite solar cells, according to a recent study published in *Science*. The discovery centers on a synthetic ionic salt named CPMAC, which originates from buckminsterfullerene (C60) and has been shown to outperform traditional C60 in solar applications.

Researchers from the King Abdullah University of Science and Technology (KAUST) played a key role in the development of CPMAC. While C60 has long been used in perovskite solar cells due to its favorable electronic properties, it suffers from stability issues caused by weak van der Waals interactions at the interface with the perovskite layer. CPMAC was engineered to address these shortcomings.

“For over a decade, C60 has been an integral component in the development of perovskite solar cells. However, weak interactions at the perovskite/C60 interface lead to mechanical degradation that compromises long-term solar cell stability. To address this limitation, we designed a C60-derived ionic salt, CPMAC, to significantly enhance the stability of the perovskite solar cells,” explained Professor Osman Bakr, Executive Faculty of the KAUST Center of Excellence for Renewable Energy and Sustainable Technologies (CREST).

Unlike C60, CPMAC forms ionic bonds with the perovskite material, strengthening the electron transfer layer and thereby enhancing both structural stability and energy output. Cells incorporating CPMAC demonstrated a 0.6% improvement in power conversion efficiency (PCE) compared to those using C60.

Though the gain in efficiency appears modest, the impact scales up dramatically in real-world energy production. “When we deal with the scale of a typical power station, the additional electricity generated even from a fraction of a percentage point is quite significant,” said Hongwei Zhu, a research scientist at KAUST.

Beyond efficiency gains, CPMAC also enhanced device longevity. Under accelerated aging tests involving high heat and humidity over 2,000 hours, solar cells containing CPMAC retained a significantly higher portion of their efficiency. Specifically, their degradation was one third that observed in cells using conventional C60.

Further performance evaluation involved assembling the cells into four-cell modules, offering a closer approximation to commercial-scale solar panels. These tests reinforced the molecule’s advantage in both durability and output.

The key to CPMAC’s success lies in its capacity to reduce defects within the electron transfer layer, thanks to the formation of robust ionic bonds. This approach circumvents the limitations posed by van der Waals forces typical of unmodified C60 structures.

Research Report:C60-based ionic salt electron shuttle for high-performance inverted perovskite solar modules

Source link

Solar Energy

Indonesia says China’s Huayou to replace LGES in EV battery project

Published

4 days ago

April 24, 2025

sarosh

Indonesia says China’s Huayou to replace LGES in EV battery project

by AFP Staff Writers

Jakarta (AFP) April 23, 2025

China’s Zhejiang Huayou Cobalt is replacing South Korea’s LG Energy Solution as a strategic investor in a multibillion-dollar project to build an electric vehicle battery joint venture in Indonesia, officials said on Wednesday.

The South Korean company, which was part of a consortium that signed a 142 trillion rupiah ($8.4 billion) “Grand Project” in 2020, announced its withdrawal from the project this week, citing factors including market conditions and the investment environment.

Energy and Mineral Resources Minister Bahlil Lahadalia said LG Energy Solution’s decision would not significantly affect the project, which aims to establish a local electric vehicle battery value chain in Indonesia.

“Changes only occur at the investor level, where LG no longer continue its involvement… and has been replaced by a strategic partner from China, namely Huayou,” Bahlil said in a statement.

“Nothing has changed from the initial goal, namely making Indonesia as the center of the world’s electric vehicle industry.”

Indonesia, home to the world’s largest nickel reserve, has been seeking to position itself as a key player in the global electric vehicle supply chain by leveraging its vast reserve of the critical mineral to attract investments.

The government decided not to move forward with the South Korean company in the project due to the long negotiation process with the firm to realise its investment, Investment Minister Rosan Roeslani said.

Rosan cited Huayou’s familiarity with Indonesia as one of the reasons why the government chose the company to succeed LG Energy Solution.

“Huayou had invested in Indonesia,” Rosan said.

“They have sources to develop the industry going forward.”

LG Energy Solution said in a statement on Tuesday that it will continue to explore “various avenues of collaboration” with the Indonesian government, including in its battery joint venture.

HLI Green Power, a joint venture between LG Energy Solution and Hyundai Motor Group, operates Indonesia’s first electric vehicle battery plant, which was launched in 2024 with a production capacity of up to 10 Gigawatt hours (GWh) of cells annually.

Source link