Developed at Soochow University in China, a hybrid solar cell with a triboelectric nanogenerator (TENG) can generate electricity from both sunlight and the motion of raindrops.
The new device integrates a solar cell with a TENG via smart design structure. In dry weather, the solar cell can generate electricity from the sun. “The TENG can also produce electricity from the mechanical energy of falling raindrops in rainy weather,” says Zhen Wen in the College of Nano Science and Technology. “In other words, our device can always generate electricity in any weather.” The device even generates electricity when rain falls at night.
Until now, no other attempt to combine a TENG with an existing solar cell to gain energy from raindrops has resulted in game-changing technology. So what is different about the hybrid device Wen and colleagues created that makes it effective? “Previous work merely put a TENG nanogenerator on a solar cell with an extra wire, which should not be a compact device,” the researcher explains, describing competing approaches as bulky and of inferior efficiency. “Our new design allows the solar cell and TENG to be integrated by a mutual electrode.” In fact, he adds: “The transparent and conducting conjugated polymer electrode is the key for the device, and it is compact with improved efficiency.”
Promise for the future
As Wen points out, the TENG nanogenerator still has a short development history in comparison with the solar cell. “We believe that it may need time to solve some technique problems before it goes to market,” the expert reckons. “However, some prototype product can emerge in the coming three to five years, since this field is developing so quickly.”
Impact on design of future hybrid devices
The innovation reported out of China could indeed influence the design of the next generation of solar cells that can plug additional energy from the rain, even in the dark. “We always dream that a commercial solar panel could harvest rain energy,” Wen says. “Considering the design in this work, I believe the time to realize our dream is getting closer.”
Combining advantages of large current and high voltage
A solar cell can generate a large current level, and a TENG can provide a high voltage level. “This device is different from any previous one single device because it can combine two advantages,” Wen emphasizes. “Due to our unique device design, it becomes a lightweight device.”
Taking their research work forward, Wen and his colleagues want to explore ways to integrate this new kind of device into mobile and flexible devices, such as electronic clothes. However, Wen says the output power efficiency would need to be further improved before practical application can be realized.
Today, thanks to the unique design, the breakthrough concept already offers the advantages of light weight and high efficiency: “We are now designing a fiber-shaped device and expect to weave them together as a fabric,” Wen reveals. “My wish is to fabricate clothing that enables to generate electricity from sunshine and raindrops and power the wearable electronic devices.”
The research is described in the article “Integrating Silicon Solar Cell with Triboelectric Nanogenerator via a Mutual Electrode for Harvesting Energy from Sunlight and Raindrops,” published in the journal ACS Nano.
Written by Sandra Henderson, Research Editor, Solar Novus Today