Crystalsilicon has been the material of choice for solar cell manufacturers since the 1950s. Crystal silicon has the highest conversion efficiency and stability compared to other similar materials, but it also has its drawbacks: transparency. But scientists from South Korea believe a solution has been found, which is to punch holes in crystalline silicon.
Transparent solar cells can bring great benefits to human renewable energy and have a wide range of applications, such as replacing windows of skyscrapers, sunroofs in cars and screens on smartphones. In the pursuit of transparency, scientists explore different materials and different solar cell designs, but they have some degree of sacrifice in terms of efficiency, transparency, and long-term stability.
But scientists at South Korea’s Ulsan National Institute of Science and the University of Korea say their new transparent solar cells will not compromise. Kwanyong Seo, co-author of the paper, said: “My team members have tested and concluded that crystalline silicon is the best material for developing glassy, efficient, highly stable and neutral-colored solar cells. This project is a crazy idea for all of us. The problem is that crystalline silicon is not transparent, so before us, no one tried to make transparent crystalline silicon with a neutral color. “
Seo and his team made a big breakthrough in this area, drilling a bunch of tiny holes in crystalline silicon. To avoid the red tones and other colors of the previously transparent solar cells, the team drilled holes in crystal linesilicon the size of human hair, allowing light to pass through.
The holes are arranged in carefully designed patterns that are invisible to the naked eye. In the test, the transparent solar cell has long-term stability, the conversion efficiency is 12.2%. This is still a significant gap from the 20-25% efficiency of commercial solar cells, but there are significant improvements over the transparent solar cells currently under development.
The team also tested the potential use of the transparent solar cell as a window. In low-angle light in the test, conventional solar cells lost about 30% of the current. In addition, the scientists found that low-angle light can reduce the current of solar cells by less than 4%.
“We want to replace the existing windows,” says Seo. We need to overcome many difficulties, such as laws and regulations. We also need mechanical stability and strength to replace the current windows in buildings with our equipment. “
The paper is published in Joule.