The report shows that the improved component is a conductive oxide film, which is now more transparent in the infrared region. Although scientists have made similar attempts before, this is the first time that a conductive oxide film has achieved higher transparency with a one-step process, and the entire process is in a stable air environment.
Photovoltaic cells and a range of other technologies can benefit from it
"The film made by the University of Luxembourg has been exposed to the air for a year and a half, and the current conductivity is still not inferior to the original." said Professor Susanne Siebentritt, head of the photovoltaic laboratory of the University of Luxembourg.
"This is a great scientific research result, not only for solar cells, but also for a range of other technologies." She added. The participating scientists in this study are also the research assistant Dr. Matěj Hála from the Photovoltaic Laboratory of the University of Luxembourg and Shohei Fujii and Yukari Inoue from TDK.
Transparent conductive oxides can be used in any device that combines electrons and light, such as light-emitting diodes (LEDs), solar cells, photodetectors, and even touch screens. In solar cells, these films must be conductive because they consist of the upper electrode. At the same time, they must also be transparent in order to transmit the captured sunlight to the lower layer-the area where the current is formed.
Photovoltaic power generation technology can benefit from this new achievement
By adding impurities, the oxide constituting the film has a conductive function. Generally speaking, aluminum-doped zinc oxide is the most widely used. In this case, aluminum can bring free electrons to zinc oxide, and these free electrons can also absorb infrared light, which means that less solar energy is passed through.
The research team of the University of Luxembourg and TDK made a series of adjustments to the process of making the film to make pure lead oxide more conductive.
"Thanks to the academic exchanges of various countries, our multidisciplinary expert group has sprouted the idea of adding an additional substance-gas plasma-to the sputtering process. After adding gas plasma, the material can still be conductive even if there is no aluminum element." Professor Siebentritt Explain that.
There are fewer free electrons, but faster
"With this new process, the conductivity of the gas plasma material is similar to that of the aluminum-doped material, but the transparency in the infrared region is better, because the decrease in the number of free electrons causes a decrease in the light absorption rate, thereby improving the solar cell's Efficiency." Dr. Matěj Hála explained.