Beautiful Science

These sunflowers are made of perovskite crystals grown on a flat, clear and thin substrate called muscovite mica. The image was captured using a scanning electron microscope by PhD student Ha Son Tung, who was supervised by Professor Xiong Qihua, ass
These sunflowers are made of perovskite crystals grown on a flat, clear and thin substrate called muscovite mica.PHOTO: NANYANG TECHNOLOGICAL UNIVERSITY

These sunflowers are made of perovskite crystals grown on a flat, clear and thin substrate called muscovite mica.

The image was captured using a scanning electron microscope by PhD student Ha Son Tung, who was supervised by Professor Xiong Qihua, associate chair for research at Nanyang Technological University's School of Physical and Mathematical Sciences.

The crystal is about 10 micrometres in size, which is smaller than the diameter of human hair.

Under specific conditions, the material self-assembles into the shape of a sunflower.

"This is very coincidental, since pervoskite's famous for its solar cell application," said Mr Ha, who added that he digitally added colour to the original black-and-white image.

The solar conversion efficiency of perovskite, compared with other solar cells, has reached 20 per cent - up from 4 per cent, in only five years.

It is considered one of the most promising materials for solar technology, said Mr Ha.

Last year, this image, titled Perovskite Flower, won silver in the Science As Art competition by the Materials Research Society in the United States.

A version of this article appeared in the print edition of The Straits Times on August 19, 2016, with the headline 'Beautiful Science'. Print Edition | Subscribe