Scientists Discover Solar Cell That May Be The Most Efficient In The World
WASHINGTON: Scientists have developed a new solar cell that converts direct sunlight into electricity at 44.5 percent efficiency and could become the most efficient solar cell in the world.
The prototype incorporates several cells stacked in a single device capable of capturing almost all of the energy in the solar spectrum, the researchers said.
The approach developed by researchers at George Washington University (GWU) in the US Is different solar panels that could be seen on the roofs or in the fields.
The new device uses photovoltaic concentrators (CPVs), which use lenses to focus sunlight on tiny microscale solar cells.
Because of their small size – less than a square millimeter – solar cells using more sophisticated materials can be developed in a cost-effective way, according to the researchers.
Matthew lumb web of George Washington University
Matthew Lumb is the lead author of the study on the new solar cell
The stacked cell is almost like a sieve for sunlight, materials specialized in each energy layer of a specific set of absorption wavelengths.
When the light circulates in the battery, a little less than half of the available energy is converted into electricity.
In comparison, the most common solar cell makes today only a quarter of the energy available in electricity.
“Approximately 99 percent of the power contained in direct sunlight reaches the earth’s surface falls between wavelengths of 250 nanometers (nm) and 2500 nm, but conventional materials for multi-junction high efficiency solar cells It can not capture the entire spectral range, “said Matthew Lumb, lead author of the study published in the journal Advanced Materials Energy.
“Our new device is able to unlock the energy stored in them long-lasting photons, which are lost in conventional solar cells, and thus provides a path to the achievement of the final multiunion solar cell,” said M. Lumb.
Although scientists have been working towards the most efficient solar cells for years, this approach has two new aspects.
Firstly, it uses a family of materials based on gallium antimonide substrates (GaSb), which are normally found in applications of infrared lasers and photodetectors.
The new GaSb-based solar cells are assembled into a structure stacked with solar cells at high efficiency grown on conventional substrates that capture solar photons shorter wavelength.
In addition, the stacking procedure uses a technique known as transfer printing, which allows for a three-dimensional assembly of these small devices with a high degree of accuracy.
Although this particular solar cell is very expensive, researchers believe it is important to show the upper limit of what is possible in terms of efficiency.
Despite the current costs of the materials involved, the technique used to create the cells is very promising, according to the researchers….