20 July 2017
Step forward for next-generation solar cells
Published online 5 July 2017
Scientists use atom-thin semiconductors to make efficient solar cells.
A research team from Saudi Arabia, Taiwan and Japan has created next-generation solar cells that are promising to be more efficient than the commonly used silicon-based cells.
Ultrathin electronic devices such as diodes, photodetectors and solar cells are mostly made by vertically stacking single layers of semiconductors using complex manufacturing techniques, but these sometimes allow for the presence of contaminants and defects at the interfaces of different layers.
However, the way Jr-Hau He from King Abdullah University of Science and Technology (KAUST), Thuwal, Saudi Arabia and his colleagues laterally placed the single layers of the semiconducting materials tungsten selenide and molybdenum sulfide enabled them to form atomically sharp monolayer junctions between different semiconductors1.
“This type of atomically thin solar cells can generate power that could even exceed the power generated by conventional silicon-based solar cells,” says He.
When connected in parallel, the solar cells showed a power conversion efficiency of 2.56% and a loss of only 5% of their original power conversion efficiency when the angle of incident light changed from 0o to 75o.
The solar cells were also able to retain 70% of their original power conversion efficiency after being used for one month.
Unlike conventional solar cells which need surface modification to reduce reflection, these solar cells can absorb sunlight from all directions without reflection.
- Tsai, M.-L. et al. Single atomically sharp lateral monolayer p-n heterojunction solar cells with extraordinarily high power conversion efficiency. Adv. Mater. http://dx.doi.org/10.1002/adma.201701168 (2017)