New solar cells can generate electricity even on rainy days

Cloudy and rainy weather often affects the power generation capacity of solar cells. By attaching a transparent nano generator to the solar cell, a Chinese research team has recently developed a device that can generate electricity by using raindrops when it rains. Researchers such as Sun Xuhui and Sun Bao of the Institute of Functional Nano and Soft Matter, Soochow University, China, reported in the latest issue of 'American Chemical Society Nano' that this hybrid device consists of a traditional silicon-based solar cell and a 'tribological nano power generation.' The latter can convert the mechanical energy of falling raindrops into electrical energy. 'Friction nanogenerator' was first proposed by the research group of Professor Wang Zhonglin from Georgia Institute of Technology. Previous research has shown that these two types of equipment can be connected together through an external wiring. In this new design, the solar cell and the 'friction nanogenerator' are integrated through a common electrode. Researchers believe that this design is simpler and greatly improves output efficiency. The researchers used a high-conductivity polymer aqueous solution to create the common electrode film of the device. Wen Zhen, the first author of the paper, told Xinhua News Agency reporters that when raindrops fall, the water droplets are triboelectrically charged with the 'tribo nanogenerator' as the friction layer, and the common electrode film acts as a charge-sensing layer to induce and export charges. Because the friction layer is transparent, it will hardly affect the incidence of sunlight, so it will not affect the normal operation of the solar cell itself. When it rains, it can also collect rainwater falling kinetic energy, which expands the range of energy collection. Under the existing large-area application conditions of silicon-based solar cells, it has a good application prospect.