At the 48th IEEE Photovoltaic Experts Conference, researchers from the Fraunhofer ISE in Germany showed how they used a photovoltaic cell to achieve 68.9% conversion under monochromatic light. Efficiency record.
The main component of the battery is gallium arsenide, which is exposed to a 858-nanometer laser.
The research team said that in addition to the traditional uses of solar cells, photovoltaic devices can also be used with lasers for efficient power transmission.
The researchers pointed out that this is the highest efficiency obtained so far to convert light into electrical energy.
In order to set an efficiency record, the research team used a thin photovoltaic cell made of gallium arsenide and applied a few micrometers thick high-reflectivity conductive mirror on the back of the remaining semiconductor structure.
The researchers said: “In photovoltaic cells, light is absorbed by the battery structure. Light can release positive and negative charges, which are conducted to the front and back of the battery contacts to generate electricity. When the incident light energy slightly exceeds the inherent semiconductor material The photovoltaic effect will play a role when the band gap energy is high. Therefore, when the monochromatic laser as the light source is matched with a suitable semiconductor compound material, theoretically high efficiency can be achieved.”
The researchers said that in this new form of energy transmission called “light energy“, laser energy is transmitted to a photovoltaic cell through the air or optical fiber. The performance of this photovoltaic cell matches the power and wavelength of the monochromatic laser.
Compared with traditional copper wire transmission, the new optical energy transmission system is conducive to applications that require electrically isolated power supplies, lightning protection, explosion protection, and electromagnetic compatibility.
Henning Helmers, head of the research team, said: “This thin-film method has two obvious advantages in terms of efficiency. First, the photons are trapped in the cell to maximize the absorption of photon energy close to the band gap. At the same time, this The heat loss and transmission loss are minimized, making the battery more efficient. Secondly, the internal photons generated by radiation recombination are captured and effectively circulated. This prolongs the effective carrier life and additionally increases the voltage.
Andreas Bett, Director of the ISE Research Institute, said: “Light energy transmission has many applications. For example, wind turbine structure monitoring; high-voltage line monitoring, fuel sensors or passive optical networks in aircraft fuel tanks; optical supply of external implants or Provide wireless power for IoT applications.”
According to reports, in April 2021, ISE researchers achieved a conversion efficiency of 26% for double-sided contact silicon solar cells, a record.
Mercom earlier reported that the III-V/Si tandem solar cell developed directly on silicon by ISE researchers set an efficiency record of 25.9%.
Post time: Jul-15-2021