Norwegian University of Science and Technology
A research team at the Norwegian University of Science and Technology (NTNU) has developed a method for manufacturing ultra-high material efficiency solar cells using semiconductor nanowires. If placed on top of traditional silicon-based solar cells, it may double the efficiency of today's silicon solar cells at low cost.
"We have a new method of using gallium arsenide (GaAs) materials in a very effective way through nanostructures, so we can increase the efficiency of solar cells by using only a small part of the commonly used materials," said Anjan Mukherjee, Electronics PhD student in the Department of Systems.
Mukherjee is the main developer of this technology. Gallium arsenide (GaAs) is the best material for manufacturing high-efficiency solar cells because of its extraordinary light absorption and electrical properties. It is usually used to make solar panels that are mainly used in space.
However, the manufacturing cost of high-quality GaAs solar cell modules is quite high, which drives the demand for technologies that can reduce the use of materials.
In recent years, researchers have realized that compared to standard planar solar cells, nanowire structures can potentially increase the efficiency of solar cells, even if the method uses fewer materials.
"Our research team found a new way to use GaAs in the nanowire structure to create ultra-high power-to-weight solar cells that are more than 10 times more efficient than any other solar cell," said Professor Helge Weman. In the NTNU Department of Electronic Systems.
The team's research has been published in the journal ACS Photonics of the American Chemical Society.
GaAs solar cells are usually grown on thick and expensive GaAs substrates, and there is little room for cost reduction.
"Our method uses a vertically standing semiconductor nanowire array structure to grow nanowires on an inexpensive and industry-friendly Si platform," Weman said.
"The most cost-effective and efficient solution is to grow dual tandem batteries. The GaAs nanowire battery on the top is grown on the Si battery on the bottom, thereby avoiding the use of expensive GaAs substrates. We have been committed to growing the top GaAs nanowire battery The cost is minimized because GaAs manufacturing cost is currently one of the main problems hindering the development of this technology,” Weman explained.
"The tiny footprint of the nanowire structure provides additional benefits because it allows the crystals in the nanowires and the interface with silicon to be of high quality. This helps to improve the performance of solar cells," said Bjorn-Ove Fimland, a professor in the same department .
Through appropriate investment and industrial-scale R&D projects, the development of this technology can be straightforward and cost-effective.
"We use a method called MBE (Molecular Beam Epitaxy) to grow nanowires. This is not a tool for mass production of materials. However, by using industrial-scale tools such as MOCVD (Metal Organic Vapor Deposition), you can Mass production of these nanowire-based solar cells," Mukherjee said.
Integrating this product on silicon cells can increase the efficiency of solar cells by as much as 40%-compared with today's commercial silicon solar cells, this means that the efficiency has doubled.
The researchers say that their method can be adjusted to allow nanowires to grow on different substrates, which may open the door to many other applications.
"We are exploring the growth of this type of lightweight nanowire structure on atomically thin two-dimensional substrates such as graphene. This may be the production of lightweight and flexible solar energy that can be used for self-powered drones, micro-satellites, and other space applications. The battery opens up huge opportunities," Mukherjee said.
References: Anjan Mukherjee, Dingding Ren, Per-Erik Vullum, Junghwan Huh, Bjørn-Ove Fimland and Helge Weman. GaAs/AlGaAs nanowire array solar cells are grown on silicon and have an ultra-high power-to-weight ratio. ACS Photonics 2021, 8, 8, 2355–2366 Publication date: August 9, 2021 https://doi.org/10.1021/acsphotonics.1c0052
GaAs/AlGaAs nanowire array solar cells grown on silicon have an ultra-high power-to-weight ratio
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Nancy Bazilchuk Norwegian University of Science and Technology nancy.bazilchuk@ntnu.no Office: 91897321
Anjan Mukherjee NTNU anjan.mukherjee@ntnu.no
Norwegian University of Science and Technology
Copyright © 2021 American Association for the Advancement of Science (AAAS)
Copyright © 2021 American Association for the Advancement of Science (AAAS)