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Puzzling out and testing new ways to improve the efficiency of cadmium telluride (CdTe) polycrystalline thin-film photovoltaic materials is a typical day in the life of National Renewable Energy Laboratory (NREL) research scientists Matthew Reese and Craig Perkins. Like any good puzzlers, they bring curiosity and keen observation to the task. These skills led them, over time, to make an intriguing observation. In fact, their discovery may prove to be a boon for the next generation of several different types of thin-film solar cells.

When fragments of solar cell material are crystallized together, or “grown” — think of a piece of rock candy growing in layers in a cup of sugar — they create a polycrystalline solar cell. With many layers come many surfaces, where one layer ends and another begins. These surfaces can cause defects that restrict the freedom of electrons to move, reducing the cell’s efficiency. As the cells are grown, researchers can introduce specific compounds that minimize the loss of electrons at these defects, in a process called “passivation.”

Reese, Perkins, and Colorado School of Mines doctoral student Deborah McGott noticed that the three-dimensional (3D) CdTe solar cells’ surfaces appeared to be covered in a very thin, two-dimensional (2D) layer that naturally eliminated surface defects. This 2D passivation layer forms in sheets on the 3D light-absorbing layer as the cell is growing, in a standard processing technique that is used around the globe. Despite the ubiquity of this 2D passivation layer, it had not been observed or reported in the research literature. Reese, Perkins, and McGott believed 2D passivation was also occurring naturally in other thin-film solar cells, like copper indium gallium selenide (CIGS) and perovskite solar cells (PSCs). They realized that this observation could lead to the development of new methods to improve the performance of many types of polycrystalline thin-film cells.

To confirm their hypothesis, they discussed it with NREL colleagues in the CdTeCIGS, and PSC research groups. Through many informal discussions involving coffee, hallway chats, and impromptu meetings, Reese, Perkins, and McGott arrived at an “aha” moment. Their CdTe and CIGS colleagues confirmed that, while their research communities were not generally trying to perform 2D surface passivation in the 3D light-absorbing layer, it was, in fact, occurring. The PSC researchers said that they had noticed a 3D/2D passivation effect and were beginning to intentionally include compounds in device processing to improve performance. The “aha” moment took on even more significance.

“One of the unique things about NREL is that we have large groups of experts with different pools of knowledge working on CdTe, CIGS, and PSC technologies,” Reese said. “And we talk to each other! Confirming our hypothesis about naturally occurring 3D/2D passivation with our colleagues was easy because we share the successes and setbacks of our diverse research in an ongoing, informal, and collaborative way. We learn from each other. It is not something that typically happens in academic or for-profit-based polycrystalline thin-film solar cell research, where information is closely held, and researchers tend to remain siloed in their specific technology.”

The details of Reese, Perkins, and McGott’s discovery are presented in the article “3D/2D passivation as a secret to success for polycrystalline thin-film solar cells,” published in the journal Joule.

Supporting Evidence in the Literature

To confirm their findings, McGott conducted an extensive literature search and found considerable supporting evidence. The literature confirmed the presence of passivating 2D compounds in each of the CdTe, CIGS, and PSC technologies. No mention was made, however, of the 2D compounds’ ability to improve device performance in CdTe and CIGS technologies. While many articles on PSC technologies noted the naturally occurring 3D/2D passivation effect and discussed efforts to intentionally include specific compounds in device processing, none suggested that this effect might be active in other polycrystalline thin-film photovoltaic technologies.

Polycrystalline thin-film solar cells are made by depositing thin layers, or a thin film, of photovoltaic material on a backing of glass, plastic, or metal. Thin-film solar cells are inexpensive, and many people are familiar with their more unique applications. They can be mounted on curved surfaces — to power consumer goods, for example — or laminated on window glass to produce electricity while letting light through. The largest market for thin-film solar cell applications, however, is for CdTe thin film on rigid glass to make solar modules. CdTe modules are deployed at utility scale, where they compete directly with conventional silicon solar modules. Currently, commercial thin-film modules are generally less efficient than the best single crystal silicon solar modules, making performance improvements a high priority for polycrystalline thin-film researchers.

Key Properties of 2D Materials

Reese, Perkins, and McGott’s team used surface science techniques combined with crystal growth experiments to show that the 2D layers existed at and passivated 3D absorber surfaces in the three leading polycrystalline thin-film photovoltaic technologies. They then analyzed the key properties of successful 2D materials and developed a set of principles for selecting passivating compounds.

Finally, the team outlined key design strategies that will allow 3D/2D passivation to be employed in polycrystalline thin-film photovoltaic technologies more generally. This is particularly important because each 3D material requires a specific passivation approach.

The literature results, combined with lab-based observations, show that 3D/2D passivation may be the secret to success in enabling next-generation thin-film solar cells, particularly if researchers freely share the knowledge developed for each technology. The lack of 3D/2D passivation may even shed light on the stalled performance improvements of some polycrystalline technologies such gallium arsenide. By drawing parallels between the three technologies, Reese, Perkins, and McGott hope to demonstrate how the knowledge developed in each can — and should — be leveraged by other technologies, an approach that is seldom seen in polycrystalline thin-film solar cell research.

CdTe, CIGS, and PSC thin-film research at NREL is funded by the Department of Energy’s Solar Energy Technologies Office. Additional funding for Reese and McGott’s research is provided by the Department of Defense’s Office of Naval Research.

Learn more about photovoltaic research at NREL.

Article courtesy of the NREL, The U.S. Department of Energy.


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Robinhood is up 160% this year, but several obstacles are ahead

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Robinhood is up 160% this year, but several obstacles are ahead

Florida AG opens probe into Robinhood. Here's the latest

Robinhood stock hit an all-time high Friday as the financial services platform continued to rip higher this year, along with bitcoin and other crypto stocks.

Robinhood, up more than 160% in 2025, hit an intraday high above $101 before pulling back and closing slightly lower.

The reversal came after a Bloomberg report that JPMorgan plans to start charging fintechs for access to customer bank data, a move that could raise costs across the industry.

For fintech firms that rely on thin margins to offer free or low-cost services to customers, even slight disruptions to their cost structure can have major ripple effects. PayPal and Affirm both ended the day nearly 6% lower following the report.

Despite its stellar year, the online broker is facing several headwinds, with a regulatory probe in Florida, pushback over new staking fees and growing friction with one of the world’s most high-profile artificial intelligence companies.

Florida Attorney General James Uthmeier opened a formal investigation into Robinhood Crypto on Thursday, alleging the platform misled users by claiming to offer the lowest-cost crypto trading.

“Robinhood has long claimed to be the best bargain, but we believe those representations were deceptive,” Uthmeier said in a statement.

The probe centers on Robinhood’s use of payment for order flow — a common practice where market makers pay to execute trades — which the AG said can result in worse pricing for customers.

Robinhood Crypto General Counsel Lucas Moskowitz told CNBC its disclosures are “best-in-class” and that it delivers the lowest average cost.

“We disclose pricing information to customers during the lifecycle of a trade that clearly outlines the spread or the fees associated with the transaction, and the revenue Robinhood receives,” added Moskowitz.

Robinhood CEO Vlad Tenev explains 'dual purpose' behind trading platform's new crypto offerings

Robinhood is also facing opposition to a new 25% cut of staking rewards for U.S. users, set to begin October 1. In Europe, the platform will take a smaller 15% cut.

Staking allows crypto holders to earn yield by locking up their tokens to help secure blockchain networks like ethereum, but platforms often take a percentage of those rewards as commission.

Robinhood’s 25% cut puts it in line with Coinbase, which charges between 25.25% and 35% depending on the token. The cut is notably higher than Gemini’s flat 15% fee.

It marks a shift for the company, which had previously steered clear of staking amid regulatory uncertainty.

Under President Joe Biden‘s administration, the Securities and Exchange Commission cracked down on U.S. platforms offering staking services, arguing they constituted unregistered securities.

With President Donald Trump in the White House, the agency has reversed course on several crypto enforcement actions, dropping cases against major players like Coinbase and Binance and signaling a more permissive stance.

Even as enforcement actions ease, Robinhood is under fresh scrutiny for its tokenized stock push, which is a growing part of its international strategy.

The company now offers blockchain-based assets in Europe that give users synthetic exposure to private firms like OpenAI and SpaceX through special purpose vehicles, or SPVs.

An SPV is a separate entity that acquires shares in a company. Users then buy tokens of the SPV and don’t have shareholder privileges or voting rights directly in the company.

OpenAI has publicly objected, warning the tokens do not represent real equity and were issued without its approval. In an interview with CNBC International, CEO Vlad Tenev acknowledged the tokens aren’t technically equity shares, but said that misses the broader point.

JPMorgan announces plans to charge for access to customer bank data

“What’s important is that retail customers have an opportunity to get exposure to this asset,” he said, pointing to the disruptive nature of AI and the historically limited access to pre-IPO companies.

“It is true that these are not technically equity,” Tenev added, noting that institutional investors often gain similar exposure through structured financial instruments.

The Bank of Lithuania — Robinhood’s lead regulator in the EU — told CNBC on Monday that it is “awaiting clarifications” following OpenAI’s statement.

“Only after receiving and evaluating this information will we be able to assess the legality and compliance of these specific instruments,” a spokesperson said, adding that information for investors must be “clear, fair, and non-misleading.”

Tenev responded that Robinhood is “happy to continue to answer questions from our regulators,” and said the company built its tokenized stock program to withstand scrutiny.

“Since this is a new thing, regulators are going to want to look at it,” he said. “And we expect to be scrutinized as a large, innovative player in this space.”

SEC Chair Paul Atkins recently called the model “an innovation” on CNBC’s Squawk Box, offering some validation as Robinhood leans further into its synthetic equity strategy — even as legal clarity remains in flux across jurisdictions.

Despite the regulatory noise, many investors remain focused on Robinhood’s upside, and particularly the political tailwinds.

The company is positioning itself as a key beneficiary of Trump’s newly signed megabill, which includes $1,000 government-seeded investment accounts for newborns. Robinhood said it’s already prototyping an app for the ‘Trump Accounts‘ initiative.

WATCH: Watch CNBC’s full interview with Robinhood CEO Vlad Tenev

Watch CNBC's full interview with Robinhood CEO Vlad Tenev

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Hyundai and Kia are betting on lower-priced EVs to ride out tariffs

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Hyundai and Kia are betting on lower-priced EVs to ride out tariffs

Korean auto giants Hyundai and Kia think lower-priced EVs will help minimize the blow from the new US auto tariffs. Hyundai is set to unveil a new entry-level electric car soon, which will be sold alongside the Kia EV2. Will it be the IONIQ 2?

Hyundai and Kia shift to lower-priced EVs

Hyundai and Kia already offer some of the most affordable and efficient electric vehicles on the market, with models like the IONIQ 5 and EV6.

In Europe, Korea, Japan, and other overseas markets, Hyundai sells the Inster EV (sold as the Casper Electric in Korea), an electric city car. The Inster EV starts at about $27,000 (€23,900), but Hyundai will soon offer another lower-priced EV, similar to the upcoming Kia EV2.

The Inster EV is seeing strong initial demand in Europe and Japan. According to a local report (via Newsis), demand for the Casper Electric is so high that buyers are waiting over a year for delivery.

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Hyundai is doubling down with plans to introduce an even more affordable EV, rumored to be the IONIQ 2. Xavier Martinet, CEO of Hyundai Motor Europe, said during a recent interview that “The new electric vehicle will be unveiled in the next few months.”

Hyundai-Kia-lower-priced-EVs
Hyundai Casper Electric/ Inster EV models (Source: Hyundai)

The new EV is expected to be a compact SUV, which will likely resemble the upcoming Kia EV2. Kia will launch the EV2 in Europe and other global regions in 2026.

Hyundai is keeping most details under wraps, but the expected IONIQ 2 is likely to sit below the Kona Electric as a smaller city EV.

Hyundai-Kia-lower-priced-EVs
Kia Concept EV2 (Source: Kia)

More affordable electric cars are on the way

Although nothing is confirmed, it’s expected to be priced at around €30,000 ($35,000), or slightly less than the Kia EV3.

The Kia EV3 starts at €35,990 in Europe and £33,005 in the UK, or about $42,000. Through the first half of the year, Kia’s compact electric SUV is the UK’s most popular EV.

Hyundai-Kia-lower-priced-EVs
Kia EV3 (Source: Kia)

Like the Hyundai IONIQ models and Kia’s other electric vehicles, the EV3 is based on the E-GMP platform. It’s available with two battery packs: 58.3 kWh or 81.48 kWh, providing a WLTP range of up to 430 km (270 miles) and 599 km (375 miles), respectively.

Hyundai is expected to reveal the new EV at the IAA Mobility show in Munich in September. Meanwhile, Kia is working on a smaller electric car to sit below the EV2 that could start at under €25,000 ($30,000).

Hyundai-Kia-lower-priced-EVs
Kia unveils EV4 sedan and hatchback, PV5 electric van, and EV2 Concept at 2025 Kia EV Day (Source: Kia)

According to the report, Hyundai and Kia are doubling down on lower-priced EVs to balance potential losses from the new US auto tariffs.

Despite opening its new EV manufacturing plant in Georgia to boost local production, Hyundai is still expected to expand sales in other regions. An industry insider explained, “Considering the risk of US tariffs, Hyundai’s move to target the European market with small electric vehicles is a natural strategy.”

Hyundai-Kia-lower-priced-EVs
2025 Hyundai IONIQ 5 (Source: Hyundai)

Although Hyundai is expanding in other markets, it remains a leading EV brand in the US. The IONIQ 5 remains a top-selling EV with over 19,000 units sold through June.

After delivering the first IONIQ 9 models in May, Hyundai reported that over 1,000 models had been sold through the end of June, its three-row electric SUV.

While the $7,500 EV tax credit is still here, Hyundai is offering generous savings with leases for the 2025 IONIQ 5 starting as low as $179 per month. The three-row IONIQ 9 starts at just $419 per month. And Hyundai is even throwing in a free ChargePoint Home Flex Level 2 charger if you buy or lease either model.

Unfortunately, we likely won’t see the entry-level EV2 or IONIQ 2 in the US. However, Kia is set to launch its first electric sedan, the EV4, in early 2026.

Ready to take advantage of the savings while they are still here? You can use our links below to find deals on Hyundai and Kia EV models in your area.

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Blink Charging just threw a lifeline to EVBox Everon customers

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Blink Charging just threw a lifeline to EVBox Everon customers

As EVBox shuts down its Everon business across Europe and North America, EV charging provider Blink Charging is stepping up to offer support to customers caught in the transition.

EVBox’s software arm Everon recently announced it’s winding down operations alongside EVBox’s AC charger business. That’s left a lot of charging station hosts and drivers wondering what comes next. Now, EVBox Everon is pointing its customers toward Blink as a recommended alternative.

Blink says it’s ready to help, whether that means keeping existing chargers up and running or replacing aging gear with new Blink chargers.

“EVBox has played a significant role in the growth of EV charging infrastructure across the UK and Mainland Europe, and we recognize the trust hosts have placed in its solutions,” said Alex Calnan, Blink Charging’s managing director of Europe. “With the recent announcement of Everon’s withdrawal from the EV charging market, it’s natural to have questions about what this means for operations. At Blink, we want to assure Everon customers that we are here to help them navigate this transition.”

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Blink says it’s able to offer advice, replacements, and ongoing network management to make the changeover as smooth as possible.

Everon users who switch to Blink will get access to the Blink Network portal via the Blink Charging app. That opens up real-time insight into charger usage and lets hosts set pricing, manage users, and download performance reports.

“At Blink, our charging technology is future-ready,” added Calnan. “With advancements like vehicle-to-grid technology on the horizon, our chargers are built to support the future of electric vehicles and charging habits.”

The company says its chargers are in stock and ready to ship now for any Everon customers looking to make the jump.

In October 2024, France’s Engie announced it would liquidate the entire EVBox group, which it said posted total losses of €800 million since Engie took over in 2017. EVBox is closing its operations in the Netherlands, Germany, and the US.


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