Nanowire technology can double the efficiency of solar cells
Nov 16, 2021
A research team at the Norwegian University of Science and Technology (NTNU) has developed a method for manufacturing ultra-high-efficiency solar cells using semiconductor nanowire materials. If used in traditional silicon-based solar cells, this method is expected to double the efficiency of today's silicon solar cells at low cost. The research paper was published in the journal ACS Photonics of the American Chemical Society.
The main developer of the new technology and NTNU PhD student Anjan Mukherjee said that their new method is very effective, using gallium arsenide materials and nanostructures, so only a small part of the commonly used materials can be used to improve solar energy. The efficiency of the battery.
Due to its extraordinary light absorption and electrical properties, gallium arsenide has become the best material for manufacturing high-efficiency solar cells, and is usually used to manufacture space solar panels. However, the manufacturing cost of high-quality gallium arsenide solar cell modules is quite high. In recent years, people have realized that compared with standard planar solar cells, nanowire structures can potentially increase the efficiency of solar cells while using fewer materials.
NTNU researcher Haig Wieman said that the team found a new way to make ultra-high-power solar cells that are more than 10 times more efficient than any other solar cell by using gallium arsenide in the nanowire structure.
Gallium arsenide solar cells are usually grown on thick and expensive gallium arsenide substrates, and there is little room for cost reduction. The new method uses a vertically standing semiconductor nanowire array structure to grow nanowires on a cheap silicon platform. Professor Wiman explained that the most cost-effective and efficient solution is to grow dual tandem cells, where the top gallium arsenide nanowire cell is grown on the bottom silicon cell, thus avoiding the use of expensive gallium arsenide substrates.
Researchers use molecular beam epitaxy to grow nanowires. Through appropriate investment and industrial-scale research and development, this technology can directly achieve cost-effectiveness. The researchers said that the integration of the product on silicon cells can increase the efficiency of solar cells to 40%, which means that compared with today's commercial silicon solar cells, the efficiency has doubled. Using new methods to adjust the growth of nanowires on different substrates may also open the door to many other applications.