According to a recent research headed by chemist Xiaoyang Zhu (University of Texas at Austin), the productivity of conventional cells (solar cells) can considerably be increased.
According to the new findings of chemist, Xiaoyang Zhu and his team using an organic plastic semiconductor material it is possible to increase the number of electrons collected from photon (of sunbeams) by 100%. Xiaoyang Zhu who is also professor of chemistry mentioned that a plastic semiconductor solar cell brings advantages. One of these advantages is the capability of producing photovoltaic cells (of this type) in a great volume at a low cost. Allied with the extensive capabilities concerning molecular design and molecular synthesis; their recent findings can open door to a new method of solar-energy conversion with more efficiency and lower prices.
In the 16th of December, Zhu along with his team published their innovative finding in Science.
The current theoretic efficacy of a silicon cell is about 31%; this is because most of the solar energy, which impacts the solar cells is too high to be transformed into electricity. This energy is later lost in the form of thermic energy. This results in about 69% of lost energy. Capturing such energy or “hot electrons” would increase the efficacy of the conversion of solar energy into electrical energy to a value close to 66%!
Going back to 2010 Zhu and his team published a research in Science; using semiconductor Nano crystals they demonstrated “hot electrons” could be captured. According to Zhu, reliable technology based upon that study is very interesting.
Zhu said that when considering the creation of new material or a new device (especially solar-energy technology) some problems appeared. One of those problems when seeking for more efficiency is that the upper mentioned 66% effectiveness can be accomplished only if a highly concentrated sunlight is used. When such problems occur, a solution has to be envisaged. The team fast found an alternative to avoid the problem. They found out that a photon produces a dark quantum or “shadow state” and then two additional electrons can be caught in order to produce more energy in the semiconductor. Xiaoyang Zhu told that if such mechanism is used, they can increase the effectiveness of the cells to 44% without needing to focus a solar beam. This will definitely increase international interest in solar energy.
This study was supported by the DOE (Department of Energy) and the National Science Foundation. Wai-lun-Chan (postdoctoral associated at the Zhu’s group) also lead the research team assisted by other postdoctoral colleagues named: Askat Jailaubekov, Loren Kaake, Luis Miaja-Avila and Manuel Ligges.