Flexible thin film solar cells that can be produced by roll-to-roll manufacturing are a highly promising route to cheap solar electricity.
Now scientists from Empa, the Swiss Federal Laboratories for Materials Science and Technology, have made significant progress in paving the way for the industrialization of flexible, light-weight and low-cost cadmium telluride (CdTe) solar cells on metal foils. They succeeded in increasing their efficiency from below eight to 11.5 percent by doping the cells with copper, as they report in the current issue of “Nature Communications”.
In order to make solar energy widely affordable scientists and engineers all over the world are looking for low-cost production technologies. Flexible thin film solar cells have a huge potential in this regard because they require only a minimum amount of materials and can be manufactured in large quantities by roll-to-roll processing. One such technology relies on cadmium telluride (CdTe) to convert sunlight into electricity. With a current market share that is second only to silicon-based solar cells CdTe cells already today are cheapest in terms of production costs. Grown mainly on rigid glass plates, these so-called superstrate cells have, however, one drawback: they require a transparent supporting material that lets sunlight pass through to reach the light-harvesting CdTe layer, thus limiting the choice of carriers to transparent materials.
The inversion of the solar cell’s multi-layer structure – the so-called substrate configuration – would allow further cost-cuttings by using flexible foils made of, say, metal as supporting material. Sunlight now enters the cell from the other side, without having to pass through the supporting substrate. The problem, though, is that CdTe cells in substrate configuration on metal foil thus far exhibited infamously low efficiencies well below eight percent – a modest comparison to the recently reported record efficiency of 19.6 percent for a lab-scale superstrate CdTe cell on glass. (Commercially available CdTe superstrate modules reach efficiencies of between 11 and 12 percent.)
Copper doping for solar cells
One way to increase the low energy conversion efficiency of substrate CdTe cells is p-type doping of the semiconductor layer with minute amounts of metals such as copper (Cu). This would lead to an increase in the density of “holes” (positive charge carriers) as well as their lifetimes, and thus result in a high photovoltaic power, the amount of sunlight that is turned into electrical energy. A perfect idea – if CdTe weren’t so notoriously hard to dope. “People have tried to dope CdTe cells in substrate configuration before but failed time and again”, explains Ayodhya Nath Tiwari, head of Empa’s laboratory for Thin Films and Photovoltaics.
His team decided to try nonetheless using high-vacuum Cu evaporation onto the CdTe layer with a subsequent heat treatment to allow the Cu atoms to penetrate into the CdTe. They soon realized that the amount of Cu had to be painstakingly controlled: if they used too little, the efficiency wouldn’t improve much; the very same happened if they “over-doped”.
The electronic properties improved significantly, however, when Lukas Kranz, a PhD student in Tiwari’s lab, together with Christina Gretener and Julian Perrenoud fine-tuned the amount of Cu evaporation so that a mono-atomic layer of Cu would be deposited on the CdTe. “Efficiencies increased dramatically, from just under one percent to above 12”, says Kranz. Their best value was 13.6 percent for a CdTe cell grown on glass; on metal foils Tiwari’s team reached efficiencies up to 11.5 percent.
The Latest Bing News on:
- Why strong solar flare didn't disrupt cell phone service or cause auroraon February 24, 2024 at 6:09 am
Solar flares, coronal mass ejections and radiation storms are different types of energy eruptions from the sun.
- Bright idea: Orange County offers partly used solar panels free. Here’s how to get yours.on February 24, 2024 at 4:00 am
A pivotal piece of Orange County history could put a free shine on someone’s future. That’s the deal of the “Great Solar Giveaway 2024” event. Some 5,808 partly used solar panels belonging to the ...
- Top 8 Cheapest Solar Panels 2024: Affordable & Good Quality Solar Companieson February 23, 2024 at 1:00 pm
DaranEner’s cheapest solar panels have received favorable feedback from customers. The panels offer affordability, with the NEO300 being highly regarded for its portability and convenience. On the ...
- Semi-Transparent Cells Could Turn Windows Into Solar Energy Collectorson February 23, 2024 at 8:32 am
As such, engineers and designers are keen to find inventive new ways to include solar cells that seamlessly blend into their surrounding environment. The idea goes that these semi-transparent ...
- How do solar panels work? Your renewable energy system explainedon February 23, 2024 at 5:48 am
Solar panels work by converting sunlight into an electric charge that produces electricity for your home. You either use the electricity or store it for later.
- Can solar flares cause cell phone outages? Here’s what experts say.on February 22, 2024 at 10:21 pm
Two powerful solar flares erupted minutes before a nationwide cellular service outage impacted millions of mobile users Thursday morning, and many people on social media quickly theorized that the ...
- Solar flares or sabotage: TikTok has theories about what happened with today’s massive cell phone outageon February 22, 2024 at 5:35 pm
Solar flares and cell phones outages spark speculation after big network connectivity problems across the United States.
- Solar cell prices hold steady as market weighs feasibility of increasing priceson February 22, 2024 at 4:01 pm
Solar cell FOB China prices have stayed unchanged, with not much real trading taking place as price negotiations for orders delivered in March are still ongoing. Mono PERC M10 and G12 cell prices ...
- Solar flares? Russian nukes? Theories swirl for what caused nationwide cell outageon February 22, 2024 at 10:16 am
It was like a game of telephone, only with no cell phone service. Theories about Thursday massive disruption swirled on social media, with blame for the widespread outage leveled at US foes Russia ...
- Powerful twin solar flares erupt from sun as cell phone outages spike across US (video)on February 22, 2024 at 7:49 am
Two outbursts from the sun occurred as widespread cellphone outages were reported throughout the United States on Thursday (Feb. 22).Two powerful solar flares erupted from the sun on the evening of ...
The Latest Google Headlines on:
[google_news title=”” keyword=”solar cells” num_posts=”10″ blurb_length=”0″ show_thumb=”left”]
The Latest Bing News on:
Thin film solar cells
- How Much Do Solar Panels Cost In 2024?on February 22, 2024 at 3:41 pm
Thin-film solar panels cost between $0.50 and $1.50 per watt, putting them at the lowest end of the price range for solar panels. These solar panels also utilize photovoltaic materials ...
- Amorphous solar cells with FIDO technology are more efficient, stable and lightweighton February 22, 2024 at 8:51 am
A group led by researchers at Nagoya University in Japan has created a material based on fullerene indanones (FIDO), which promises to improve the durability of next-generation solar cells. Durability ...
- Photovoltaic Materials for High-Efficiency Solar Cells: Recent Developmentson February 22, 2024 at 5:21 am
Solar energy is central in the transition towards greener and more sustainable practices. The global shift towards sustainable energy has created a demand for advanced photovoltaic materials for ...
- Thin-Film Photovoltaic Market revenue to surpass USD 29 Billion by 2036, says Research Nesteron February 22, 2024 at 3:30 am
Solar cells account for 16% of the total electricity produced by ... standards to USD 130 to 180 per ton along with the Emissions Trade System price in 2030. Thin-Film Photovoltaic Market: Key ...
- Physicists develop new solar cell design for better efficiencyon February 20, 2024 at 1:56 pm
Physicists at Paderborn University have used complex computer simulations to develop a new design for significantly more efficient solar cells than previously available. A thin layer of organic ...
- Types of solar panels: What sort of solar panel should you choose?on February 6, 2024 at 4:00 pm
Monocrystalline, polycrystalline, thin film, thermal-photovoltaic… all these terms and more are used (often at the same time) to describe solar panels, but what do they mean? And does it really ...
- Flexible silicon solar cells that can roll upon February 5, 2024 at 4:01 pm
Highly efficient silicon solar cells that are as flexible as a sheet of paper could offer a lightweight power source for applications such as uncrewed aerial vehicles while cutting the cost of ...
- Types of Solar Panels for Homeson February 4, 2024 at 4:00 pm
You’ll need a larger roof if you opt for polycrystalline solar panels, as they require more space than monocrystalline. Thin-film panels are a newer type of solar panel used less often for homes ...
- 8 Most Efficient Solar Panels (2024)on February 4, 2024 at 4:00 pm
Thin-film panels offer the least efficiency and ... They’re less expensive than mono panels but have lower efficiency. Solar panel backing also affects your panel’s energy production.
The Latest Google Headlines on:
Thin film solar cells
[google_news title=”” keyword=”thin film solar cells” num_posts=”10″ blurb_length=”0″ show_thumb=”left”]