
Scanning electron microscope images show an array of zinc-oxide nanowires (top) and a cross-section of a photovoltaic cell made from the nanowires, interspersed with quantum dots made of lead sulfide (dark areas). A layer of gold at the top (light band) and a layer of indium-tin-oxide at the bottom (lighter area) form the two electrodes of the solar cell. Images courtesy of Jean, et al/Advanced Materials
One advantage of quantum dot-based PVs is that they can be tuned to absorb light over a much wider range of wavelengths
Using exotic particles called quantum dots as the basis for a photovoltaic cell is not a new idea, but attempts to make such devices have not yet achieved sufficiently high efficiency in converting sunlight to power. A new wrinkle added by a team of researchers at Massachusetts Institute of Technology (MIT)—embedding the quantum dots within a forest of nanowires—promises to provide a significant boost.
Photovoltaics (PVs) based on tiny colloidal quantum dots have several potential advantages over other approaches to making solar cells: They can be manufactured in a room-temperature process, saving energy and avoiding complications associated with high-temperature processing of silicon and other PV materials. They can be made from abundant, inexpensive materials that do not require extensive purification, as silicon does. And they can be applied to a variety of inexpensive and even flexible substrate materials, such as lightweight plastics.
But there’s a tradeoff in designing such devices, because of two contradictory needs for an effective PV: A solar cell’s absorbing layer needs to be thin to allow charges to pass readily from the sites where solar energy is absorbed to the wires that carry current away—but it also needs to be thick enough to absorb light efficiently. Improved performance in one of these areas tends to worsen the other, says Joel Jean, a doctoral student in MIT’s Department of Electrical Engineering and Computer Science (EECS).
“You want a thick film to absorb the light, and you want it thin to get the charges out,” he says. “So there’s a huge discrepancy.”
That’s where the addition of zinc oxide nanowires can play a useful role, says Jean, who is the lead author of a paper to be published in Advanced Materials. The paper is co-authored by chemistry professor Moungi Bawendi, materials science and engineering professor Silvija Grade?ak, EECS professor Vladimir Bulovi?, and three other graduate students and a postdoctoral researcher.
These nanowires are conductive enough to extract charges easily, but long enough to provide the depth needed for light absorption, Jean says. Using a bottom-up growth process to grow these nanowires and infiltrating them with lead-sulfide quantum dots produces a 50% boost in the current generated by the solar cell, and a 35% increase in overall efficiency, Jean says. The process produces a vertical array of these nanowires, which are transparent to visible light, interspersed with quantum dots.
“If you shine light along the length of the nanowires, you get the advantage of depth,” he says. But also, “you decouple light absorption and charge carrier extraction, since the electrons can hop sideways onto a nearby nanowire and be collected.”
One advantage of quantum dot-based PVs is that they can be tuned to absorb light over a much wider range of wavelengths than conventional devices, Jean says.
The Latest Bing News on:
Quantum dot-based photovoltaics
- "Theoretical Studies on the Effect of Confinement on Quantum Dots Using the Brus Equation"on December 3, 2023 at 7:48 pm
[1] Mn-doped ZnS quantum dots as a room-temperature phosphorescent probe for analysis of glutamic acid in foodstuff 2 ...
- SmartDope: The “Self-Driving Lab” That Unlocks Quantum Dot Secrets in Hours – Instead of Yearson November 14, 2023 at 4:00 pm
“These particular quantum dots are of interest because they hold promise for next generation photovoltaic devices and other photonic and optoelectronic devices,” Abolhasani says. “For example, they ...
- Autonomous lab helps find quantum dots with highest yield in hourson November 14, 2023 at 2:18 am
For electronic and photonic devices, researchers have been using perovskites, the same material that is helping improve photovoltaic ... used is called quantum dots. Quantum dots have a high ...
- Quantum dots found in mere hours thanks to high-tech autonomous labon November 12, 2023 at 3:59 pm
“These particular quantum dots are of interest because they hold promise for next generation photovoltaic devices and other photonic and optoelectronic devices,” says study corresponding author Milad ...
- Colloidal Quantum Dot Optoelectronics and Photovoltaicson November 12, 2023 at 2:43 pm
Maintenance to the cambridge.org website is scheduled for 13 November at 6am – 9am GMT. The site will be unavailable during this time. Purchasing will also be unavailable 11 November 5pm GMT – 12 ...
- Preparation of F-passivated ZnO for quantum dot photovoltaicson November 9, 2023 at 4:01 pm
Hence, it is urgent to explore new materials for photovoltaics. Among various materials, PbSe colloidal quantum dots (CQDs) are promising candidates for photovoltaics because its photoactive range can ...
- Preparation of F-passivated ZnO for quantum dot photovoltaicson November 9, 2023 at 4:01 pm
Hence, it is necessary to explore new materials for photovoltaics. PbSe colloidal quantum dots (CQDs) are promising candidates for photovoltaics because its photoactive range can cover the whole ...
- Tiny Dots, Big Impact: The Luminous World of Quantum Dotson November 6, 2023 at 4:01 pm
By the late ’90s and early 2000s, quantum dots found uses in fields like biology, displays, photovoltaics, and lasers. Throughout the 2010s, quantum dot technology advanced. In 2015, Philips ...
- Stable PbS colloidal quantum dot inks enable scalable preparation of infrared solar cells by blade coatingon November 6, 2023 at 4:01 pm
Developing clean and low-cost solar photovoltaic power is an important ... of a 1.55 eV perovskite top-cell and 1.0 eV PbS quantum dots (QDs) bottom-cell can achieve an ideal power conversion ...
The Latest Google Headlines on:
Quantum dot-based photovoltaics
[google_news title=”” keyword=”quantum dot-based photovoltaics” num_posts=”10″ blurb_length=”0″ show_thumb=”left”]
[/vc_column_text]
The Latest Bing News on:
Solar cells
- Cornwall New County Hall work on solar panels in car parkon December 7, 2023 at 5:10 am
The council says the canopy of 543 solar panels that will cover the entire New County Hall visitors’ carpark will significantly reduce ...
- Solar panels to be installed in public hospitals countrywideon December 7, 2023 at 4:53 am
This move is aimed at reducing carbon emissions within the health sector while relying on 100,000 Community Health Promoters to spearhead climate change mitigation efforts.
- Researchers use wood to create low-cost, long-lasting solar cellson December 7, 2023 at 3:57 am
Building organic solar cells from wood materials improves their eco-friendliness through this innovative approach.
- Where do solar panels go to die?on December 7, 2023 at 2:23 am
This coverage is made possible through a partnership with IPR and Grist, a nonprofit independent media organization dedicated to telling stories of climate solutions and a just future. This story was ...
- Midsummer and the EU Sign Agreement on EU Grant for New Swedish Solar Cell Factoryon December 6, 2023 at 10:36 pm
Negotiations on the conditions for the grant from the EU towards the construction of a new mega-factory for the production of thin film solar cells in Sweden by Swedish solar energy company Midsummer ...
- Exclusive | ALMM for solar panels may be implemented from April 2024, say govt officialson December 6, 2023 at 9:19 pm
The list was kept in abeyance to boost the number and capacity of solar installations in the country. As a result, domestic manufacturers were hit by the huge imports of components. The implementation ...
- Unlocking Sustainable Power With Organic Solar Cells Lead The Green Energy Revolutionon December 6, 2023 at 9:16 pm
Discover how this innovation addresses the sustainability challenge and paves the way for wood-based solar cells, offering efficient, affordable, and environmentally conscious energy solutions.
- Energy firms “won’t offer” long contracts to solar panel ownerson December 6, 2023 at 4:00 pm
Two in three energy companies that offer long-term fixed price contracts for supplying gas and electricity are reluctant to take on customers who own solar panels, according to research by the Dutch ...
- Dallas jury finds solar panel company mistreated homeowner and awards $500,000on December 6, 2023 at 3:45 pm
Jesus Hernandez of Irving says he was fooled by Southern Solar into buying solar panels. The same thing has happened to other homeowners. The difference ...
- Researchers use wood materials to create reliable organic solar cellson December 6, 2023 at 12:04 pm
One of nature's most common organic materials—lignin—can be used to create stable and environmentally friendly organic solar cells. Researchers at Linköping University and the Royal Institute of ...
The Latest Google Headlines on:
Solar cells
[google_news title=”” keyword=”solar cells” num_posts=”10″ blurb_length=”0″ show_thumb=”left”]