VATIS UPDATE Article

Developed by Hong Kong Polytechnic University, China, a new type of solar cell is drawing attention in Hong Kong, with a possible application to wearable devices and other equipment. A group of researchers led by Charles Chee Surya, invented perovskite-silicon tandem solar cells. With the perovskite solar cell functioning as the top layer, it can harvest the short-wavelength light, while the bottom layer coated with silicon is designed to absorb the long wavelength light. The two layers enabled the module to achieve the “world’s highest” power conversion efficiency of 25.5%.

Previously, the Swiss team’s 22.8% was the highest. In addition to the usability of the material, the group estimates that power generation costs will be about 30% lower than with conventional silicon cells. “The market for perovskite solar cells is going to grow quite substantially in the future,” said Surya. He explained that perovskite cells can be applied to a wide range of products, such as wearable devices and sensors for home appliances.

That said, there are safety and durability problems in putting perovskite solar cells into practical use. The use of lead, on which regulations have tightened around the globe, is raising concerns, and the power conversion efficiency, which declines in a few days, will also become a barrier to application. A joint effort between industry and academia will likely be the key to establishing mass production technology.