Various metal nanoparticles have been tried before, but can have drawbacks such as absorbing energy, or increasing corrosion.
In the case of the silicon particles, they don’t absorb light, nor do they interact with other materials in the cell, according to ITMO University in St Petersburg, which worked with St Petersburg State University and workers in Italy and the USA.
“Dielectric particles don’t absorb light, so they don’t heat up,” said ITMO researcher Aleksandra Furasova. “They are chemically inert and don’t affect the stability of the battery. Besides, being highly resonant, such particles can absorb more light of a wide range of wavelengths. Due to special layout characteristics, they don’t damage the structure of the cells. These advantages allowed us to enhance cells efficiency up to almost 19%. So far, this is the best-known result for this particular perovskite material with incorporated nanoparticles,”
The particular perovskite is MAPbI3 perovskite, with the silicon particles between the mesoporous TiO2 transport layer and active layers.
“Now we can further try to use such particles for other types of perovskites with increased efficiency and stability,” said fellow researcher Sergey Makarov. “Apart from that, the nanoparticles themselves can be modified in order to enhance their optical and transport properties.”
The work is published in Advanced Optical Materials in the paper ‘Resonant silicon nanoparticles for enhanced light harvesting in halide perovskite solar cells‘.