A new way to image solar cells in 3-d _ berkeley lab

The Molecular Foundry’s Edward Barnard is part of a team of scientists that developed a new way to see inside solar cells. Electricity history timeline (Credit: Marilyn Chung)

“To make big gains in photovoltaic efficiency, we need to see what’s happening throughout a working photovoltaic material at the micron scale, both on the surface and below, and our new approach allows us to do that,” says Edward Barnard, a principal scientific engineering associate at the Molecular Foundry. Npower gas price reduction He led the effort with James Schuck, the director of the Imaging and Manipulation of Nanostructures facility at the Molecular Foundry.

The imaging method is born out of a collaboration between Molecular Foundry scientists and Foundry users from PLANT PV Inc., an Alameda, California-based company. Bp gas prices nj While fabricating new solar cell materials at the Molecular Foundry, the team found that standard optical techniques couldn’t image the inner-workings of the materials, so they developed the new technique to obtain this view. Grade 6 electricity unit test Next, scientists from the National Renewable Energy Laboratory came to the Molecular Foundry and used the new method to study CdTe solar cells.

To develop the approach, the scientists modified a technique called two-photon microscopy (which is used by biologists to see inside thick samples such as living tissue) so that it can be applied to bulk semiconductor materials.

The method uses a highly focused laser beam of infrared photons that penetrate inside the photovoltaic material. Kd 7 electricity socks When two low-energy photons converge at the same pinpoint, there’s enough energy to excite electrons. Electricity freedom system These electrons can be tracked to see how long they last in their excited state, with long-lifetime electrons appearing as bright spots in microscopy images. Gas unlimited houston texas In a solar cell, long-lifetime electrons are more likely to reach an electrode.

In addition, the laser beam can be systematically repositioned throughout a test-sized solar cell, creating a 3-D map of a solar cell’s entire optoelectronic dynamics.

The 3-D rendering on the left is a cadmium telluride solar cell without cadmium chloride treatment. K gas constant The image on the right shows a solar cell that has been treated with cadmium chloride . Gas monkey live It “lights up” much more uniformly throughout the material, both in the grains and the spaces in between. 93 gas near me (Credit: Berkeley Lab)

The method has already shed light on the benefits of treating CdTe solar cells with cadmium chloride, which is often added during the fabrication process.

Scientists know cadmium chloride improves the efficiency of CdTe solar cells, but its effect on excited electrons at the micron scale is not well understood. Electricity vs gasoline Studies have shown that the chlorine ions tend to pile up at grain boundaries, but how this changes the lifetime of excited electrons is unclear.

Thanks to the new imaging technique, the researchers discovered the cadmium chloride treatment increases the lifetime of excited electrons at the grain boundaries, as well as within the grains themselves. 3 main gas laws This is easily seen in 3-D images of CdTe solar cells with and without the treatment. Electricity how it works The treated solar cell “lights up” much more uniformly throughout the material, both in the grains and the spaces in between.

“Scientists have known that cadmium chloride passivation improves the lifetime of electrons in CdTe cells, but now we’ve mapped at the micron scale where this improvement occurs,” says Barnard.

The new imaging technique could help scientists make more informed decisions about improving a host of thin-film solar cell materials in addition to CdTe, such as perovskite and organic compounds.

“Researchers trying to push photovoltaic efficiency could use our technique to see if their strategies are working at the microscale, which will help them design better test-scale solar cells—and eventually full-sized solar cells for rooftops and other real-world applications,” he says.

The research was supported by the Department of Energy’s Office of Science and by a SunShot Initiative award from the Office of Energy Efficiency and Renewable Energy.

The U.S. K electric company Department of Energy SunShot Initiative is a collaborative national effort that aggressively drives innovation to make solar energy fully cost-competitive with traditional energy sources before the end of the decade. Bad gas 6 weeks pregnant Through SunShot, the Energy Department supports efforts by private companies, universities, and national laboratories to drive down the cost of solar electricity to $0.06 per kilowatt-hour. C gastronomie traiteur avis Learn more at energy.gov/sunshot.

Lawrence Berkeley National Laboratory addresses the world’s most urgent scientific challenges by advancing sustainable energy, protecting human health, creating new materials, and revealing the origin and fate of the universe. Electricity water analogy animation Founded in 1931, Berkeley Lab’s scientific expertise has been recognized with 13 Nobel prizes. Gas cap light The University of California manages Berkeley Lab for the U.S. Gas key staking tool Department of Energy’s Office of Science. 76 gas station jobs For more, visit www.lbl.gov.

DOE’s Office of Science is the single largest supporter of basic research in the physical sciences in the United States, and is working to address some of the most pressing challenges of our time. Electricity song omd For more information, please visit science.energy.gov. Gas leak los angeles Additional information