Multi-junction solar cells are both the most efficient type of solar cell on the market today and the most expensive type of solar cell to produce. In a proof-of-concept paper, researchers from North Carolina State University detail a new approach for creating multi-junction solar cells using off-the-shelf components, resulting in lower cost, high-efficiency solar cells for use in multiple applications.
Multi-junction, or stacked, solar cells are currently the most efficient cells on the market, converting up to 45% of the solar energy they absorb into electricity. The cells are constructed by stacking semiconductors with varying bandgaps on top of one another, thereby allowing the cell to absorb differing wavelengths of solar radiation. However, these cells are much more expensive to produce than less efficient thin solar films.
“We want to create high efficiency solar cells at a reasonable cost,” says Salah Bedair, Distinguished Professor of Electrical and Computer Engineering at NC State and lead author of the research. “Silicon-based thin solar cells are very popular because the material has around 20% efficiency and the cells cost about 1/10th what a multi-junction solar cell costs. And other low cost, lower efficiency materials are gaining popularity as well. If we could create stacked solar cells using this existing technology we would be well on our way to reaching our goal.”
However, you cannot merely stack different solar cells on top of each other – the different materials are structurally incompatible, and so charges cannot pass through them to be collected. To solve that problem in current multi-junction solar cells heavily doped metals are used to create a tunnel junction between the various layers – adding significant expense and complexity to the multi-junction solar cell’s creation.
Bedair and his team developed a simpler approach, utilizing intermetallic bonding to bond solar cells made of different materials. In a proof-of-concept, the team stacked an off-the-shelf gallium arsenide solar cell on top of a silicon solar cell.
“In multi-junction solar cells the tunnel junction enables electric connectivity by acting as a metal-to-metal connection,” Bedair says. “In our system, indium serves as a shortcut to that. The existing metal contacts of the individual cells are covered with indium films. The indium films bond to themselves easily at room temperature under low pressure. The result is a solar cell made of two different materials that is mechanically stacked and electrically connected.
“With this technique we are able to take advantage of inexpensive, off-the-shelf solutions without having to develop all new technology. Manufacturers could simply tweak their existing products slightly to increase their efficiency in multi-junction solar cells, rather than having to create new products.”
A patent application has been submitted for the work. The authors are interested in collaborating with potential academic and industry partners.
The Latest on: Multi-junction solar cells
via Google News
The Latest on: Multi-junction solar cells
- New Solar Tech Produces 50% More Energy Than Silicon Cellson October 9, 2019 at 11:03 am
“What we’re trying to do is create a high-efficiency CPV system in the form factor of a traditional silicon solar panel,” says Giebink. To do this, the researchers embed tiny multi-junction solar ...
- New Solar Cell "Most Efficient Ever"on September 27, 2019 at 5:00 pm
The breakthrough cell was developed using a structure called a “multi-junction solar cell.” In this type of device, individual PV cells are made of layers, and each layer captures a portion of the ...
- Fraunhofer ISE Sets Two Records for the Efficiency of Silicon-Based Monolithic Triple-Junction Solar Cellson August 30, 2019 at 3:58 am
Using a combination of multiple absorber materials, these multi-junction photovoltaic cells exploit the energy from the solar spectrum significantly better than conventional silicon solar cells. The ...
- Inter-metallic bonding stacks GaAs and Si solar cellson June 26, 2019 at 4:11 am
Inter-metallic bonding could remove unwanted carrier barriers from multi-junction solar cells assembled by stacking finished single-junction cells, according to North Carolina State University. “We ...
- New approach stacks up for multi-junction solar cellson June 26, 2019 at 4:07 am
A new approach to creating multi-junction solar cells with off-the-shelf components could lead to photovoltaic devices that are more efficient and cheaper to make. This is the claim of researchers ...
- Researchers Create Multi-Junction Solar Cells from Off-the-Shelf Componentson June 24, 2019 at 10:25 am
Multi-junction solar cells are both the most efficient type of solar cell on the market today and the most expensive type of solar cell to produce. In a proof-of-concept paper, researchers from North ...
- Researchers create multi-junction solar cells from off-the-shelf componentson June 23, 2019 at 5:00 pm
In a proof-of-concept paper, researchers detail a new approach for creating multi-junction solar cells using off-the-shelf components, resulting in lower cost, high-efficiency solar cells for use in ...
- Global Multi-junction Solar Collector Market key Vendors, Trends, Analysis, Segmentation, Forecast to 2016-2022on May 5, 2019 at 11:18 pm
Multi-junction Solar Cell is one of the best technologies for achieving a high sunlight to electricity conversion ratio. Theoretically, an infinite-junction cell can obtain a maximum power conversion ...
- Fraunhofer ISE achieves efficiency record for silicon multi-junction cellon January 8, 2019 at 4:39 am
Researchers at Germany’s Fraunhofer Institute have achieved a record 22.3% efficiency for a silicon based, multi-junction solar cell, through advances made in tandem cells. Researchers have been ...
via Bing News