via EMPA
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:
Solar cells
- Global Biohybrid Solar Cell Market to See Massive Growth of USD 2.95 Billion By 2030on May 24, 2022 at 2:26 am
The growing use of solar cells in the residential and commercial sectors will boost demand for biohybrid solar cells around the world.Newark, N, May 24, 2022 (GLOBE NEWSWIRE) -- As per the report ...
- Council considers installing more solar panels as its energy bills doubleon May 24, 2022 at 2:03 am
A council in Lincolnshire plans to expand its solar panel installation programme to tackle rising energy bills. North Kesteven District Council has seen the amount of money paid for energy double in ...
- Interested in Solar Panels? Here Is Some Advice.on May 24, 2022 at 2:00 am
Buying a solar energy system can be expensive and confusing. Here are some things to think about if you are in the market for solar panels.
- Gallium doping and solar cell degradationon May 24, 2022 at 1:21 am
German scientists have conducted a series of experiments on gallium-doped silicon solar cells to understand the causes of degradation in PV cells and modules treated with gallium rather than boron.
- A new conducting polymer complex to create stable and fully printable organic solar cellson May 23, 2022 at 6:40 am
In recent years, engineers worldwide have been trying to develop more sustainable technologies to produce electrical energy. One of the most promising among these solutions are organic solar cells.
- Heterojunction solar cell with 25.18% efficiency, 85.42% fill factoron May 23, 2022 at 5:05 am
Researchers in China have fabricated a heterojunction solar cell with a 244.63 cm2 Czochralski n-c-Si wafer. They used light soaking to improve the dark conductance of the hydrogenated amorphous ...
- Solar panels in Georgia: Ways to avoid scams and how decide if a system is right for your homeon May 22, 2022 at 11:30 am
Solar arrays and systems are growing in popularity for their financial and environmental benefits. When it comes to solar, don’t be afraid to ask questions and scrutinize system sellers.
- New Quantum Well Solar Cell Just Set a World Record For Efficiencyon May 22, 2022 at 11:01 am
Scientists keep on pushing the efficiency of solar panels higher and higher, and there's a new record to report: a new solar cell has hit 39.5 percent efficiency under the standard 1-sun global ...
- Solar Panel Scams: How to Avoid Them and the Biggest Red Flagson May 22, 2022 at 11:00 am
Solar panels are becoming more mainstream as the residential solar industry in the United States continues to rapidly grow. In fact, the solar market has now surpassed 3 million solar panel ...
- Researchers developed invisible, machine-washable solar cell technology for clothingon May 19, 2022 at 10:12 am
The discrete nature of the solar cells protects them—and makes the clothes more attractive, the physics and design researchers say. Promising applications include work and outdoor clothing, and ...
The Latest Google Headlines on:
Solar cells
The Latest Bing News on:
Thin film solar cells
- Heterojunction solar cell with 25.18% efficiency, 85.42% fill factoron May 23, 2022 at 5:05 am
Researchers in China have fabricated a heterojunction solar cell with a 244.63 cm2 Czochralski n-c-Si wafer. They used light soaking to improve the dark conductance of the hydrogenated amorphous ...
- Exclusive: Start-Up Offers Copper Paste As A Cost-Effective Alternative To Silver In Solar Panelson May 22, 2022 at 8:22 am
Within the solar power industry, silver is a crucial material within the manufacturing of photovoltaic panels. Silver is turned into a paste that is loaded into the silicon wafers within the panel.
- Thin-film Solar Cell Market Trends, Size, Share, Growth, Industry Analysis, Product, Application, Advance Technology and Forecast 2029 – VMRon May 21, 2022 at 2:06 pm
The “Thin-film Solar Cell Market” research report provides significant value on the state of the industry. This report provides detailed information on the industry base, productivity, strengths, ...
- Solvius rolls out ultra-thin solar panels at Northampton Saints stadiumon May 20, 2022 at 6:43 am
UK-based greentech startup Solivus has completed the installation of more than 600 ultra-thin-layer solar panels on the roof of Premiership rugby club Northampton Saints' stadium.
- Thin Film Photovoltaic Market Reflect Impressive Growth Rate to During 2021-2031on May 20, 2022 at 3:34 am
Overview The use of renewable energy around the world has increased considerably over the years. The depleting ...
- Developing Thin-film Solar Cells Without the Economic and Environmental Costson May 16, 2022 at 1:44 am
For instance, copper indium gallium selenide (CIGSe) is a thin-film solar cell that offers several advantages over traditional silicon solar cells. Thin-film solar cells are about 100 times thinner, ...
- Amorphous Silicon Thin Film Solar Cell Market Trends, Opportunities and Growth by 2030on May 15, 2022 at 5:00 pm
There is an increase in the easy availability and low manufacturing cost of different sizes and shapes of silicon thin film solar cells. This is anticipated to boost the growth of amorphous ...
- Towards more efficient, non-toxic, and flexible thin-film solar cellson May 12, 2022 at 8:04 am
Climate change, one of the major global concerns today, has made it clear that fossil fuels are detrimental to our environment and are not a sustainable source of energy. It is imperative to adopt ...
- Towards more efficient, non-toxic, and flexible thin-film solar cellson May 11, 2022 at 5:00 pm
For instance, copper indium gallium selenide (CIGSe) is a thin-film solar cell that offers several advantages over traditional silicon solar cells. Thin-film solar cells are about 100 times ...