Cambridge Photon Technology for Exceeding the Efficiency Limits
Solar power is one of the major renewable energies used in the world. Considering solar power, photovoltaics is defined as decarbonised power generating type and more focus now on modern industry. The reason behind this can be the less expensive of made solar modules. However, although the cheap manufacturing and higher investment in this type, it is difficult to achieve the climate targets for 2050.
The technology of solar modules has the challenge of improving the efficiency against its nature. The Shockley-Queisser limit which defines the efficiency of single-junction cells mentions its amount as around 29% for commercial silicon cells. Since it, the Cambridge Photon Technology comes as a good effort in labs to exceed the theoretical maximum.
How does it work?
In a solar cell, normally there is a fixed bandgap in the semiconductor material and every photon which has higher energy than the bandgap absorbs into it and generates electrons. However, the extra energy above the bandgap is wasted when absorbing photons.
In Cambridge Photon Technology, a process called singlet fission is used to solute this issue. Here, an exciton is created when absorbing the photon by the semi-conductor and electrostatically the electron is bound to the hole which is left behind. This is called an electron-hole pair. Under the singlet fission process, the energy of an electron-hole pair splits into two lower pairs which are equal to the bandgap and the electron-hole pairs can be harvested using quantum dots.
This technology is a new step in solar power generation. While using the technology the efficiency of the output will be increased up to 40% with the silicon perovskite tandem cells. However, there is an issue of using soluble lead in silicon perovskite cells which is a toxicant and environmental pollutant. Because of it, the scientific testing team of this technology comments to recycle the cells carefully at the end of the life of cells. If this technology comes to the current market with a good solution for this matter, this will be a huge step in cost saving for energy in the building environment.
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