New Pathway Emerges To Improve Polycrystalline Thin-Film Solar Cell Performance
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 CdTe, CIGS, 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.
Europe’s first teledriving (remotely driving) service is entering the US market and intends to setup shop in Sin City to begin. Vay is establishing its new US headquarters in downtown Las Vegas, where it will begin testing its teledriving service by dropping off and picking up rental EVs to customers around the city.
Vay is a German teledriving specialist based in Berlin that has taken a remote-first approach to driverless vehicles in which an operator drives a given EV from a dedicated hub. Vay is aiming to gradually introduce more autonomous driving functions in its system as they become more safe and are permitted to do so.
For now, however, the service relies on teledrivers, whose immediate focus is on the driverless transportation of rental EVs to customers. Those customers can then hop in the EV, drive off and then park whenever they are done, enabling Vay to step back in and remotely drive the vehicle back to base.
After operating a vehicle in Hamburg this past February, Vay declared itself the first and only company to drive a car on European public roads with no one inside. We’ve personally experienced this same approach to rideshare mobility in Las Vegas when we went for a ride with Halo.Car.
With its sights now set on the US, Vay will have to compete with Halo.Car in Vegas – the home of its new headquarters.
Vay to compete in growing driverless EV market in Vegas
Following its plans for expanded certification to operate driverless vehicles in Europe, Vay shared details of its expansion to the US, beginning in Las Vegas. The US entity will be lead by general manager Caleb Varner, who joined Vay in late 2022 after leaving Uber where he was director, global general manager, and co-founder of Uber Rent & Valet. Varner spoke:
I am excited to be a part of Vay and launch our service in the US. Vay’s teledriving technology and innovative approach has the potential to reshape the way people move – not only is that a huge business opportunity, but also a service that we see missing from today’s transportation ecosystem. The broader team at Vay is excited about taking this german-born technology and using it to change the way Americans move and building a future with reduced personal car ownership.
To begin, Varner will work closely with Vay cofounder and CEO Thomas von der Ohe to implement Vay’s teledriving technology in the US market that supports the launch of its own remotely driven mobility service. Von der Ohe also spoke to Vay’s new home in Vegas as a kickoff in the US:
We are excited to enter the US mobility market. Our team is talking to stakeholders in various states and has started to work on launching an initial service. The market is ready and the responses we have received so far from regulators, city governments, and potential customers in the US show that it’s a very dynamic market that we will be exploring in the near future!
Like Europe, the approach will begin with remote deliveries of rental EVs around Vegas, but certain permits and certifications are required. Luckily, Vay has the support of Las Vegas’ International Innovation Center, located in the downtown Arts District. Vay’s new headquarters sits within this office which remains part of an investment in economic development in the city.
I guess I will have to go to Vegas and take a test ride in one of Vay’s driverless cars. Twist my arm!
FTC: We use income earning auto affiliate links. More.
Toyota’s largest plant globally is going electric. The company revealed Wednesday it would assemble its new three-row electric SUV at its Georgetown, Kentucky, facility starting in 2025. The new SUV will be Toyota’s first US-assembled EV as the market continues to surpass expectations.
Toyota’s first US-assembled EV will be in Kentucky
“Toyota Kentucky set the standard for Toyota vehicle manufacturing in the US and now we’re leading the charge with BEVs,” Susan Elkington, president of Toyota Motor Manufacturing, Kentucky, explained.
The Toyota Kentucky plant is the company’s largest manufacturing facility globally, with the capability to produce 550,000 vehicles annually, and will now lead Toyota’s vehicle carbon reduction efforts in the US.
Toyota says the batteries for its three-row electric SUV will come from the company’s new battery factory in North Carolina. The plant was initially revealed in late 2021. Today’s announcement from Toyota reveals the plant will receive an additional $2.1 billion investment, bringing the total to nearly $6 billion.
Sean Suggs, president of Toyota Battery Manufacturing at the North Carolina facility, commented on the new funding, saying:
With this proactive infrastructure investment, we will be able to quickly support future expansion opportunities to meet growing customer need.
The NC plant will produce lithium-ion batteries with six production lines (four for hybrids and only two for EVs).
The Governor of Kentucky, Andy Beshear, said through a $591 million investment for future projects in Scott County, Toyota is committed to retaining 700 full-time jobs.
Although Toyota didn’t reveal any new details of its first US-assembled EV coming in 2025, we know it will be a three-row electric SUV as part of ten new electric cars planned to launch globally.
Toyota aims to sell 1.5 million EVs globally with the new models by 2026 as it looks to keep pace in the rapidly expanding electric car market.
Apart from the company’s first global EV, the bZ4X, Toyota has released an electric sedan, the bZ3, in China and teased upcoming models, including a sport crossover and family SUV.
Electrek’s Take
Since passing last August, the Inflation Reduction Act (IRA) has attracted well over $100 billion in private-sector investment in EVs, batteries, and manufacturing. Toyota is one of many automakers and suppliers that have revealed plans to build on US soil.
That being said, with its first US-assembled EV arriving in 2025, will it still be too little too late for the automaker?
Either way, Toyota is doing what it should have done years ago. It’s building its EV supply chain capabilities with battery factories while retooling manufacturing facilities. In addition, Toyota is developing a dedicated EV platform that will help streamline production and double the range of future electric models with more efficient batteries, according to the company.
With the latest slew of announcements from Toyota, the company is noticeably accelerating the pace of EV development. Perhaps, after watching EV makers like Tesla and BYD steal market share, Toyota is looking toward the future rather than the past.
FTC: We use income earning auto affiliate links. More.
Environment
Former footballer Drogba is E1’s newest team owner ahead of first electric boat racing season
The UIM E1 World Championship electric boat racing league has found its latest team as it prepares to launch its inaugural season later this year. Former Chelsea and Ivory Coast footballer Didier Drogba and his partner Gabrielle LeMaire have signed on as owners of the fourth E1 racing team to join the growing league.
The UIM E1 World Championship is a nascent electric boat racing league created by Formula E and Extreme E founder, Alejandro Agag, and Rodi Basso – a former director of Motorsport at McLaren with a background in Formula 1 engineering.
We’ve been following the new sport’s progress for over a year as it has evolved from testing its all-electric RaceBird boats, to a growing league of teams led by some familiar names. Venice emerged as the inaugural E1 race team in April of 2022, and was soon followed by team Mexico owned by Formula 1 driver Sergio Perez.
Early this year, we shared news that tennis great Rafael Nadal had signed on as E1’s next team owner, bringing his native Spain into the fold to compete on the water. As the young championship series continues to develop (and tries) to fill all ten of its initial team slots this year, it has found its latest team owner in soccer (or football) legend Didier Drogba.
Team Drogba joins E1 donning the Ivory Coast flag
E1 announced the addition of Team Drogba to the UIM Championship this morning, which will be co-owned and managed with the footballer’s partner, Gabrielle LeMaire – a successful businesswoman and marketing expert. E1 cofounder and CEO Rodi Basso spoke about what the new Team Drogba owners bring to the league:
This team is so exciting for the E1 Series, blending diversity, inclusion and sustainability with a fire to compete and win. They are a dynamic duo that show how important it is to have equal representation and opportunities for men and women in motorsport, from the boardroom to the cockpit. And their commitment to ocean health and technological change will help take E1’s message further and wider. It’s exciting to see the fleet take shape and there’s more big announcements in the pipeline.
Similar to his new rival “Rafa” Nadal, Drogba’s foundation supports sustainable developments outside of the competitive arenas to make a positive impact on the planet. The former footballer and his partner also help provide a positive impact on the lives of African children living in poverty.
Together, the new E1 owners hope Team Drogba can help the new E1 series reach a global audience and inspire it to join the race to create a more sustainable world. Drogba spoke to the ownership opportunity and the people that have inspired him:
Sport and sustainability together, it’s a winning combination. Gabrielle and I are both fierce competitors so we’re going to build a strong team. We’re inspired by legends such as Senna and Schumacher, but most especially by Lewis Hamilton, winning F1 championships, breaking barriers and acting as a leader for a new generation of pilots.
Pollution has caused the destruction and loss of coastal habitats around the world. The degradation of our underwater eco-systems poses a series threat to marine life and livelihoods of coastal communities. So we want to have a positive impact through the accelerated development of clean technologies and inspiring change. But we’re also going to have fun for a great cause. Rafa and Checo, get ready! We are coming for you. And we’re here to win!
The inaugural UIM E1 World Championship is scheduled to begin later this year as race
organizers state they will continue to accelerate preparations, promising more teams and confirmed race venues soon. Better hurry.
Electrek’s Take
This is another big get by E1 as it looks to bring as much hype to season 1 as possible… whenever that may be. The original schedule was originally anticipated to begin this past spring, but we still seem to be a ways away as E1 is now saying “late 2023” for a championship series kickoff.
The nascent series now has four teams, but has always hoped to begin racing with at least ten, so it’s going to have to hustle to find more owners quickly to get a viable competition together.
Although I do want to see E1 racing begin sooner rather than later, I don’t mind waiting because I’m genuinely unsure what I’m waiting for, meaning I’m not even sure what to expect in electric boat racing. The prospect of it looks promising, and the adjacent focus on foundations and the environment is a big plus – similar to Formula E. People love a brand with a positive cause.
I’m looking forward to seeing what countries/teams/owners join in next and how well season one goes. I’d very much like to see a competition in person, but E1 has to get there first. I’ll be watching!
FTC: We use income earning auto affiliate links. More.
-
Sports7 months ago‘Storybook stuff’: Inside the night Bryce Harper sent the Phillies to the World Series
-
Technology2 years ago
Game consoles were once banned in China. Now Chinese developers want a slice of the $49 billion pie
-
Sports2 years ago
Team Europe easily wins 4th straight Laver Cup
-
Politics2 years ago
Have the last few wobbly weeks seen a turning point for Johnson as PM?
-
Business8 months agoBank of England’s extraordinary response to government policy is almost unthinkable | Ed Conway
-
Politics2 years ago
Yvette Cooper promoted and Lisa Nandy to shadow Gove on levelling up brief in Labour reshuffle
-
Business8 months agoLiz Truss’s ‘favourite’ economist says chancellor ‘took his eye off ball’ and ‘overstepped the mark’ with mini-budget
-
Videos8 months ago
World leaders come together for Queen Elizabeth’s funeral