The process of making solar cells just got simpler, more effective, and less expensive.
Researchers from UC Berkeley and DOE’s Lawrence Berkeley National Laboratory (Berkeley Lab) have found a special substance that could be utilized to make solar cells more easily, the team stated.
This material, which has been described earlier this year in the journal Science Advances, is a crystalline solar material with an embedded electric field, also referred to as “ferroelectricity.”
This breakthrough makes it possible to produce solar cell devices that are more effective, less expensive, and easier to make.
How it works
Solar cells are necessary for solar panels to convert solar energy into electricity. For these solar cells to distinguish between positive and negative charges, an electric field is needed.
Manufacturers often invest a significant sum of money to dope each layer of the solar cell with chemicals that segregate the positive and negative charges to form this field. This indicates that electrons go from the device’s negative to positive sides, which contributes to its performance and stability.
The novel ferroelectric material, created in the lab from cesium germanium tribromide (CsGeBr3 or CGB), offers a quicker and more affordable method of creating solar cell devices. The polarization of CGB materials means that one side of the crystal naturally accumulates positive charges while the other accumulates negative ones. Therefore, no material doping is required.
The substance is not only lead-free “halide perovskite,” an emerging class of low-cost and simple-to-produce solar materials, but it is also ferroelectric. Lead is typically present in the highest-performing halide perovskites. It is well recognized that this lead pollutes our environment and endangers the general public’s health. The new material the researchers found has the added benefit of being lead-free and maintaining performance.
According to co-senior author Peidong Yang, a senior faculty scientist in Berkeley Lab’s Materials Sciences Division and professor of chemistry and materials science and engineering at UC Berkeley, “if you can imagine a lead-free solar material that not only harvests energy from the sun but also has the bonus of having a natural, spontaneously formed electric field – the possibilities across the solar energy and electronics industries are pretty exciting.”
How CGB can be put to use
According to co-senior author Ramamoorthy Ramesh, who at the time of the study was a professor of materials science and engineering at UC Berkeley and a senior faculty scientist in Berkeley Lab’s Materials Sciences Division, CGB can not only lower the cost of making solar cells, but it could also be used to advance a new generation of switching devices, sensors, and super-stable memory devices that react to light.
Additionally, the researchers discovered that CGB’s light absorption is adjustable, spanning the visible to ultraviolet light spectrum (1.6 to 3 electron volts), an excellent range for enticing high energy conversion efficiencies in a solar cell, according to Yang. He pointed out that typical ferroelectrics hardly ever have this kind of tunability.
What the future may bring
There is still work to be done after years of perfecting the research. Although there is still work to be done before the CGB material may debut in a commercial solar device, Ye Zhang, the paper’s lead author and a UC Berkeley graduate student researcher in Yang’s lab at the time, is encouraged by their first findings.
This salt-like ferroelectric perovskite substance is very adaptable, he added. We are eager to put it to the test in a genuine photovoltaic gadget.