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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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First savings hits Navee XT5 Pro long-range off-road e-scooter for $1,400, Anker SOLIX 60,000mAh power station $108, Lectric, more

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First savings hits Navee XT5 Pro long-range off-road e-scooter for ,400, Anker SOLIX 60,000mAh power station 8, Lectric, more

Our mid-week Green Deals is headlined by a surprise first-ever holiday deal on the brand-new Navee XT5 Pro Long-Range Off-Road Electric Scooter at $1,400, which boasts some serious premium upgrades. Right behind it, we have Anker’s SOLIX C200 DC Compact Power Station, and its larger C300 counterparts, that start from $108, as well as a roundup of Lectric’s three e-bikes getting up to $500 price cuts and $220 bundles that start from $1,399, Bluetti’s current 48-hour Christmas flash sale through December 18, and much more waiting for you below. And don’t forget about the hangover deals that are collected together at the bottom of the page, like yesterday’s Velotric Christmas e-bike Gift Season Sale, the new $999 low on Heybike’s dual-battery Hauler cargo e-bike, and more.

Head below for other New Green Deals we’ve found today and, of course, Electrek’s best EV buying and leasing deals. Also, check out the new Electrek Tesla Shop for the best deals on Tesla accessories.

First savings just hit Navee’s newest feature-packed XT5 Pro long-range off-road electric scooter for $1,400

Navee’s official Amazon storefront is undercutting the brand’s direct Christmas Sale pricing on its brand-new XT5 Pro Long-Range Off-Road Electric Scooter for $1,399.99 shippedafter clipping the on-page $200 off coupon. This model just hit the market early last month with a $1,500 price tag, which is where it’s still priced direct from the brand. At Amazon, however, it started off priced at $1,700 and dropped to $1,600 right before Black Friday, with today’s deal being the first official chance at cash savings that we’ve spotted. While this deal lasts, you’re getting $100 off the going rate that sets the bar for future discounts, while also upgrading your commutes/joyrides with the brand’s take on a superscooter.

The most high-end of Navee’s e-scooter lineup that even outpaces the flagship ST3 Pro, this new XT5 Pro Long-Range Electric Scooter is an off-roading superscooter that comes with bolstered durability from its carbon steel frame, while also being the second series to boast the brand’s unique damping arm suspension system. It arrives equipped with a 750W motor that can peak as high as 2,200W for seriously monstrous power, with the entire thing powered by a 596.7Wh battery. This combination gives it a travel range of up to 46.6 miles on a single six-hour charge (with a 1.5-hour flash charging feature available), maxing out at 31 MPH top speeds for the thrill seekers amongst you. It even comes with an add-on option through a 468Wh external battery (sold separately) that increases the mileage with up to 34 miles of extra travel.

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As Navee’s XT5 Pro electric scooter is a more premium commuter, it should be no surprise that it comes loaded with a premium array of features, including smart features like Apple Find My, Bluetooth proximity locking/unlocking, app-based setting customization, and more. Your riding experience is also further heightened by the stock features that include a triple braking system (dual front and rear disc brakes, as well as a rear regenerative EABS brake), 12-inch off-road tubeless tires, an auto-on headlight, mecha-style logo lamps in the stem, a brake-activated taillight, front and rear built-in turn signals, the brand’s traction control system, a 5-inch full color display, and much more.

As I mentioned, alongside this surprise Navee XT5 electric scooter deal, the brand also has its ongoing Christmas Sale with up to 30% discounts still going right now, which offers its e-scooters at some of the best rates starting from $200.

Anker SOLIX C200 DC power station on rock with drone, projector, and speaker

Get 60,000mAh/192Wh support for devices from Anker’s SOLIX C200 DC power station at $108 for Xmas, more from $162

As part of its ongoing Christmas Sale, Anker SOLIX is offering its C200 DC 60,000mAh/192Wh Compact Power Station at $108.49 shipped, which matches in price at Amazon while also beating out the current price of the predecessor PowerCore Reserve by $7. While it carries a $200 MSRP, you can find it starting lower at $170 at Amazon, with discounts over the year having taken the costs as low as $100, most recently during Black Friday through Cyber Monday over two weeks ago. You’re looking at the third-best price we have tracked while the $62 savings last ($92 off the MSRP), only beaten out by that $100 low and $105 rates that sporadically pop up. If you want to go bigger, you can also find the C300 DC and C300 AC 90,000mAh models starting from $162.

If you want to learn more about these compact power stations, be sure to check out our original coverage of these Christmas deals here. You can also go even larger by taking advantage of Anker’s current SOLIX Christmas Sale deals, with up to 65% discounts across its entire power station lineup that starts from $162.

man standing with Lectric ONE e-bike

Save up to $720 on these three Lectric e-bikes with price cuts to lows starting from $1,399 for Xmas

Looking back in on Lectric’s ongoing Christmas Holiday Sale event, we wanted to shine a spotlight on the three e-bikes receiving rare price cuts over the usual free bundle packages – a first for so many models at once. The biggest of these price cuts that also retains a bundle is Lectric’s ONE e-bike Long-Range Belt-Drive Commuter e-bike with a $220 FREE bundle of gear at $1,899 shipped. This entire package would normally run you $2,619 at full price, with a repeat of the $500 price cut we’ve been seeing more frequently since Labor Day to its all-time lowest tracked price, along with a FREE rear cargo rack and fender set. While the deadline to receive it before Christmas has passed, you can still secure it and all the other e-bikes with some of their best deals to kick-off your new year with a new commuting option.

If you want to learn more about this premium e-bike, or the other models getting Christmas price cuts, be sure to check out our original coverage of these deals here, while you can also browse the brand’s full Christmas lineup here.

woman using Bluetti Elite 10 mini power station to charge laptop on plane

For 48 hours, you can pick up Bluetti’s latest Elite 10 Mini power station at a new $109 Xmas flash sale low (Save $90), more

As part of its ongoing Christmas Sale, Bluetti has a 48-hour flash sale running that is taking up to $199 off three different offers, with a notable standout in the Elite 10 Mini Power Station for $109 shipped, which sadly cannot be stacked with the exclusive 5% off savings code, but does beat out its Amazon pricing by $10. While carrying a $239 MSRP direct from the brand, you can find it starting lower at Amazon for $199, with the holiday discounts that started last week having only taken the costs down to $149, before falling to $119 and then $109 during this flash sale window. While these $90 savings ($130 off the MSRP) last through December 18, you’re able to score it at a new all-time low price, with another flash offer being two of these stations for $199 shipped.

If you want to learn more about this mini power station, or browse the full lineup of temporary deals, be sure to check out our original coverage of this flash sale here.

RENPHO foot massager next to Christmas tree and presents
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Anker eufy solar smart security camera mounted on outdoor wall in rain
Lectric e-bike Christmas banner

Best Winter EV deals!

Best new Green Deals landing this week

The savings this week are also continuing to a collection of other markdowns. To the same tune as the offers above, these all help you take a more energy-conscious approach to your routine. Winter means you can lock in even better off-season price cuts on electric tools for the lawn while saving on EVs and tons of other gear.

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Toyota launches the new Urban Cruiser EV, an ‘authentic’ entry-level electric SUV

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Toyota launches the new Urban Cruiser EV, an 'authentic' entry-level electric SUV

The Urban Cruiser is Toyota’s second fully electric SUV, but it adds some meaningful upgrades over the outgoing bZ4X.

Meet the new Toyota Urban Cruiser electric SUV

Based on a new dedicated EV platform, Toyota calls the Urban Cruiser “an authentic SUV” in terms of design and performance.

Toyota launched the new entry-level electric SUV in Europe with two lithium iron phosphate (LFP) battery pack options: 49 kWh or 61 kWh. The smaller (49 kWh) battery is only available with a 142 hp (106 kW) front-wheel-drive (FWD) motor, rated with a WLTP driving range of 344 km (214 miles).

The larger 61 kWh version is available with FWD or all-wheel drive (AWD) powertrains, delivering WLTP driving ranges of 426 km and 395 km, respectively. The AWD version delivers a combined 181 hp (135 kW).

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Toyota said all Urban Cruiser variants can tow braked loads of up to 750 kg (1,650 lbs). With DC fast charging, the electric SUV can recharge from 10% to 80% in around 45 minutes.

Toyota-Urban-Cruiser-EV-price
The 2026 Toyota Urban Cruiser EV (Source: Toyota)

To improve efficiency, unlock faster charging, and boost driving range, Toyota added a heat pump and battery preconditioning feature as standard.

Thanks to the new dedicated EV platform, the interior is open and spacious. With sliding and split-folding rear seats, the Urban Cruiser rivals “the load-carrying capabilities of larger SUVs,” Toyota said.

Toyota-Urban-Cruiser-interior-space
The interior of the 2026 Toyota Urban Cruiser EV (Source: Toyota)
Toyota-Urban-Cruiser-interior
The interior of the 2026 Toyota Urban Cruiser EV (Source: Toyota)

Measuring 4,285 mm long, 1,800 mm wide, and 1,640 mm tall, the electric SUV is slightly bigger than its popular Yaris Cross. It also gains extra interior space thanks to an extended wheelbase of 2,700 mm (+140 mm compared to the Yaris Cross).

The infotainment system consists of a 10.25″ driver display and a 10.1″ multimedia touchscreen with wireless Apple CarPlay and Android Auto.

Toyota-Urban-Cruiser-front
The 2026 Toyota Urban Cruiser EV (Source: Toyota)

All Urban Cruiser models are equipped with standard safety features such as Brake Support System, Adaptive Cruise Control, Lane Keep Assist, and Traffic Sign Recognition.

In Germany, the Urban Cruiser EV is on sale, priced from €31,990 ($37,500). Financing is available from €340.41 ($400) a month.

Toyota’s new entry-level electric SUV follows the launch of the refreshed bZ4X. In 2026, Toyota will introduce the C-HR+, bZ4X Touring, and Hilux BEV electric pickup.

For those in the US, Toyota is not expected to launch the Urban Cruiser in the States. However, the new and much-improved 2026 Toyota bZ is among the few EVs in the US with starting prices under $35,000. Next year, it will launch the C-HR, which is expected to be even more affordable.

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Tesla throws ‘cringe’ anti-union concert for Giga Berlin employees ahead of vote

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Tesla throws 'cringe' anti-union concert for Giga Berlin employees ahead of vote

Tesla has reportedly thrown a “Giga-Event” for its employees at Gigafactory Berlin, featuring German rapper Kool Savas. The goal? To rally the troops ahead of a critical union vote. The result? A “cringe” performance involving a Cybertruck, failed “Elon” chants, and some anti-union propaganda.

We have been covering the ongoing tensions between Tesla and IG Metall, the powerful German metalworkers’ union, for years now. While Tesla has managed to fend off a complete union takeover of the works council in the past, the union has gained ground in a vote last year, and a new election is looming.

Tesla’s strategy to counter this seems to be… distinct.

According to a new report from Handelsblatt, Tesla management organized a private “Giga-Event” on December 2 to “boost morale” and, apparently, to explicitly campaign against IG Metall.

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The centerpiece of the event was a performance by famous German rapper Kool Savas. And this is where things reportedly got cringe.

Witnesses and a video provided to the German newspaper described the scene as incredibly awkward. Savas reportedly drove onto the stage in a Tesla Cybertruck, which is a rare sight in Europe, and attempted to hype up the crowd of factory workers.

The report states that the rapper tried to start an “Elon, Elon” chant, but the crowd of employees refused to join in. He changed references of ‘Mercedes’ to ‘Tesla’ in his song.

Tesla employees weren’t into it at all, and the rapper admitted after five songs:

“You guys are tough, man. You guys are really tough. Tesla, what’s wrong with you?

When the applause for Tesla as a “great employer” was lukewarm at best, Savas reportedly asked the audience if they had a “stick up their ass” (Stock im Arsch).

You can’t make this stuff up.

But it wasn’t just about a rapper struggling to read the room. The event was held with the backdrop of an upcoming work council vote.

In the last one in 2024, IG Metall managed to elect the biggest faction, but fell short of a majority.

Now, with Tesla’s sales crashing in Europe and Elon Musk’s popularity plummeting to a new low, management is scared that IG Metall could make the gains needed to control a majority of the workers’ council.

Tesla Gigafactory Berlin manager André Thierig took some shots at the union in his speech at the event, according to Handelsblatt’s report.

The good news is that he announced a 4% wage increase for employees, but he falsely claimed that they would have only gotten two if IG Metall held collective bargaining power.

On the other hand, IG, which welcomed the wage increase, claimed that Tesla needs to increase salaries by another 30% to be on par with the auto industry in Germany.

Furthermore, the report claims that Thierig suggested that Tesla’s expansion plans at the factory, including recently announced battery production, is dependent on the results of the upcoming work council election in early 2026.

IG Metall chief Otto sees a pattern at Tesla:

For years, the message has been: if you work hard, don’t join IG Metall, and dutifully elect the management-appointed works council, the factory will be expanded. Then you’ll all have unprecedented opportunities for advancement.

He sees this as a threat to control employees.

While Tesla reiterated that jobs for the 11,000 employees at Gigafactory Berlin are secured, there are growing concerns as Tesla’s sales in Europe have crashed more than 30% in 2025.

Electrek’s Take

One thing is clear: the union is having a positive impact on Tesla workers.

I doubt Tesla would be offering a 4% wage increase right before a union vote if people weren’t flirting with the idea of joining IG Metall.

What I dislike is the anti-union rhetoric. It is not needed. Let the union make its case, management make theirs, and let the employees choose. That’s it.

If you are a good employer, you don’t need to hire a rapper to tell your employees that you are a good employer.

As for job security for Tesla employees in Germany, I think there’s room for concern.

Thierig noted on stage that Model Y was still the best-selling EV in Europe, which is true, but it’s also true that sales are down 30% in Europe in 2025. And that’s compared to 2024, when sales were down 10% year-over-year.

Tesla’s situation in Europe is undeniably not great.

The automaker was expected to bring several vehicle programs to Giga Berlin, but the factory has now been operational for almost 4 years and still only produces the Model Y.

I think the only reasonable hope the factory has is the potential addition of the Tesla Semi program. Other than that, I see it shrinking rather than expanding.

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