Chinese researchers unlock nanorod spacing control for more efficient solar cells

A team led by Prof. Mingtai Wang at the Hefei Institutes of Physical Science has developed a breakthrough method to control the spacing of titanium dioxide nanorods without changing their size, significantly improving solar cell efficiency.

Researchers from the Chinese Academy of Sciences have devised a new way to grow titanium dioxide nanorod arrays (TiO₂-NA) with tunable density, allowing for better performance in solar energy applications without compromising nanorod dimensions.

Published in Small Methods, the study addresses a long-standing issue in nanomaterials engineering: the interdependence of nanorod size, length, and density. Traditionally, adjusting one parameter altered the others, limiting the effectiveness of devices such as solar cells and photocatalysts.

Prof. Mingtai Wang’s team overcame this by fine-tuning the hydrolysis stage during precursor film preparation, leading to smaller anatase nanoparticles that serve as uniform seeds for rutile-phase nanorod growth. This innovation allowed the researchers to control nanorod density independently of size.

Using the new TiO₂-NA films in CuInS₂ solar cells, the team achieved power conversion efficiencies exceeding 10%, peaking at 10.44%. Their Volume-Surface-Density model further explained how nanorod spacing impacts light absorption, charge separation, and carrier transport.

This advancement opens new possibilities in clean energy and optoelectronics, offering precise nanostructure control for next-generation solar technologies.

Copied