Photo Credit: UCLA Samueli Engineering

Materials scientists from the UCLA Samueli School of Engineering have developed a powerful thin-film solar cell that generates more energy from sunlight than average solar panels, as a result of its double-layer design, according to UCLA.

The device is made of an inexpensive compound of lead and iodine, known as perovskite, that has proven to be very efficient at capturing energy from sunlight. A thin layer of the perovskite is sprayed onto a commercially available solar cell, while the solar cell that forms the bottom layer of the device is made of a compound of copper, indium, gallium and selenide, or CIGS, creating a new cell that successfully converts 22.4 percent of the incoming energy from the sun, versus the previous record of 10.9 percent by a group at IBM’s Thomas J. Watson Research Center in 2015.

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Researchers from the University of California, Riverside recently combined photosynthesis and physics to make a key discovery that could lead to highly efficient solar cells.

Nathan Gabor, a physicist, began exploring photosynthesis when he asked himself a fundamental question in 2010: Why are plants green? This question probed him to combine his physics training with biology.
Over the past six years, Gabor has been rethinking energy conversion in light of these questions. His goal was to make solar cells that more efficiently absorb intermittent energy from the sun and increase past the current 20 percent efficiency. In this, he was inspired by the plants that had evolved over time to do exactly what he hoped solar cells would be able to do.

This from University of California, Riverside:

[The scientists] addressed the problem by designing a new type of quantum heat engine photocell, which helps manipulate the flow of energy in solar cells. The design incorporates a heat engine photocell that absorbs photons from the sun and converts the photon energy into electricity.

Surprisingly, the researchers found that the quantum heat engine photocell could regulate solar power conversion without requiring active feedback or adaptive control mechanisms. In conventional photovoltaic technology, which is used on rooftops and solar farms today, fluctuations in solar power must be suppressed by voltage converters and feedback controllers, which dramatically reduce the overall efficiency.

Read the full article.

At the core of the research, Gabor and his team are looking to connect quantum mechanical structure to the greenest plants.

Image: CC0 Public Domain

An interdisciplinary team of researchers based out of the University of Illinois at Chicago believes they may have just changed the game in solar cell technology.

According to the recently published study, the team promises a solar cell that not only harvests energy, but cheaply and efficiently transforms atmospheric carbon dioxide into useable hydrocarbon fuel – all with a little help from the sun.

The new development differs from typical solar technology, where the cells convert sunlight into energy to be stored in batteries or other energy storage devices. Instead, the new research uses solar cells in a way similar to organic photosynthesis, just amplified.

By capturing dangerous greenhouse gases and converting them into alternative, clean fuels, the researchers believe a farm full of these “artificial leaf” solar cells could begin to significantly reduce the amount of carbon dioxide in the environment and help shift the energy landscape toward more green alternatives.

“The new solar cell is not photovoltaic—it’s photosynthetic,” says Amin Salehi-Khojin, senior author of the study. “Instead of producing energy in an unsustainable one-way route from fossil fuels to greenhouse gas, we can now reverse the process and recycle atmospheric carbon into fuel using sunlight.”

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MIT researcher have developed the first steps to creating the thinnest, lightest solar cell ever made.

Through a unique fabrication method, the researchers are moving toward the development of a solar cell so thin it could blow away. Instead of a solar cell’s typical makeup, the MIT researchers have opted for a unique fabrication of creating each layer at the same time.

This from Popular Science:

Solar cells are typically made up of layers of photovoltaic materials and a substrate, such as glass or plastic. Instead of the usual method of fabricating each layer separately, and then depositing the layers onto the substrate, the MIT researchers made all three parts of their solar cell (the cell, the supportive substrate, and the protective coating) at the same time, a method that cuts down on performance-harming contaminants. In the demonstration, the substrate and coating are made from parylene, which is a flexible polymer, and the component that absorbs light was made from dibutyl phthalate (DBP). The researchers note that the solar cell could be made from a number of material combinations, including perovskite, and it could be added to a variety of surfaces such as fabric or paper.

Read the full article.

To put the thinness of the solar cell in perspective, it is approximately 1/50th the thickness of a strand of hair. The light weight means that its power-to-weight ratio is particularly high, with an efficiency output of about 6 watts per gram (400 times higher than silicon-based solar cells).

The final trial for the researcher will be to translate the lab work to the real world, making it scalable and practical for commercial use.

The development of ultralight, ultrathin solar cells is on the horizon due to a new semiconductor call phosphorene.

A team of researchers from Australian National University have developed an atom-thick layer of black phosphorus crystals through a process that utilizes sticky tape.

“Because phosphorene is so thin and light, it creates possibilities for making lots of interesting devices, such as LEDs or solar cells,” said lead researcher Dr. Yuerui (Larry) Lu.

The fabrication of this phosphorene is similar to that of graphene, bringing the new material to a thickness of just 0.5 nanometers. With phosphorene’s novel properties, doors are opening for a new generation of solar cells and LEDs.

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The new arrangement of photovoltaic materials includes bundles of polymer donors (green rods) and neatly organized fullerene acceptors (purple, tan).
Image: UCLA

A team of UCLA scientists are delivering good news on the solar energy front with the development of their new energy storage technology that could change the way scientists think about solar cell design.

Taking a little inspiration from the naturally occurring process of photosynthesis, the researchers devised a new arrangement of solar cell ingredients to make a more efficient cell.

“In photosynthesis, plants that are exposed to sunlight use carefully organized nanoscale structures within their cells to rapidly separate charges — pulling electrons away from the positively charged molecule that is left behind, and keeping positive and negative charges separated. That separation is the key to making the process so efficient,” said Sarah Tolbert, senior author of this research and published ECS author.

PS: Check out Tolbert’s recently published open access paper in the Journal of The Electrochemical Society entitled, “The Development of Pseudocapacitive Properties in Nanosized-MoO₂.”

The currently dilemma in solar cell design revolves around developing a product that is both efficient and affordable. While conventional silicon works rather well, it is too expensive to be practical on a large scale. More engineers and researchers have been moving to replace silicon with plastic, but that leads to efficiency levels taking a hit.

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Image: Antalexion

With climate change being a continually rising global dilemma, many scientist have turned their attention to research in the area of renewable energy sources. Even with some of the most brilliant minds working on improving efficiency and price of solar cells, they are still not widely used due to the high cost of materials used to develop the them. Now, a scientist may be on the path to cracking the code on material prices of solar cells by using nanotechnology.

Elijah Thimsen, assistant professor at the School of Engineering & Applied Science at Washington University in St. Louis, worked in conjunction with a team of engineers at the University of Minnesota to develop a technique to increase the performance of electrical conductivity.

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The new solar battery stores power by “breathing” air to decompose and re-form lithium peroxide.
Credit: Yiying Wu/Ohio State University

Is it a solar cell? Is it a rechargeable battery? Well, technically it’s both.

The scientists at Ohio State University have developed the world’s first solar battery that can recharge itself using light and air. The findings from the patent-pending device were published in the October 3, 2014 issue of the journal Nature Communications.

This from Ohio State University:

Key to the innovation is a mesh solar panel, which allows air to enter the battery, and a special process for transferring electrons between the solar panel and the battery electrode. Inside the device, light and oxygen enable different parts of the chemical reactions that charge the battery.

Read the full article here.

The university plans to license the solar battery to industry.

“The state of the art is to use a solar panel to capture the light, and then use a cheap battery to store the energy,” said Yiying Wu, professor of chemistry and biochemistry at Ohio State University. “We’ve integrated both functions into one device. Any time you can do that, you reduce cost.”

The device also tackles the issue of solar energy efficiency by eliminating the loss of electricity that normally occurs when electrons have to travel between a solar cell and an external battery. Where typically only 80 percent of electrons make it from the solar cell into the battery, the new solar battery saves nearly 100 percent of electrons.

Want to know more about what’s going on with solar batteries? Check out the latest research in ECS’s Digital Library and find out what our scientists think the future looks like.