Distinct particle shapes can regulate, improve performance in technologies that use light.

Researchers at Curtin University have found that flat shapes in nanomaterials allow for improved molecular attachment – a discovery potentially leading to advancements in optoelectronics, which involve devices that either produce or use light to perform their functions. This includes a wide range of everyday technologies such as LEDs and TV screens, medical diagnostics and solar panels.

Adjusting their original shape was proven to optimize zinc sulfide nanoplatelets, teasing a massive improvement in several nanotechnology applications.

The study, published in the Journal of the American Chemical Society, details significant strides in understanding how the shape of zinc sulfide nanocrystals affected ligands' ability to adhere to their surface and affect their properties. (Ligands are ions or neutral molecules that bond to a central metal atom or ion to form a new chemical compound.)

Lead author and Associate Professor Guohua Jia from Curtin's School of Molecular and Life Sciences describes how research uncovered a way to increase the number of molecules that adhere to the tiny surfaces of nanocrystals.

"Ligands play an important role in controlling the behavior and performance of zinc sulfide nanocrystals in various important technologies," Jia said. "In a discovery that could open new possibilities for developing smarter, more advanced devices, our study found flatter, more even particles called nanoplatelets allow more ligands to attach tightly, compared to other shapes like nanodots and nanorods."

The researchers discovered that the density of surface ligands or molecules that cling to the surface of nanocrystals is influenced by their overall shapes. By changing the shape of the particles, the researchers were able to improve their performance in various applications and regulate how they interacted with their environment.

"From brighter LED lights and screens to more efficient solar panels and more detailed medical imaging, the ability to control particle shapes could revolutionize product efficiency and performance," said Jia, "The ability to efficiently manipulate light and electricity is central to the advancement of faster, more efficient, and more compact electronic systems. This includes LEDs, which convert electricity into light and are used in everything from light bulbs to TV screens as well as solar cells that convert light into electrical energy, powering devices using sunlight."

The researchers attributed the increased ligand density in nanoplatelets to their uniformly flat surfaces, which enabled molecules to stack tightly together. In contrast, the more irregular surfaces of nanodots and nanorods led to less efficient stacking of the ligands.

"Other devices that could be advanced by this discovery include photodetectors that sense light and convert it into an electrical signal, such as in cameras and sensors, plus laser diodes used in fiber-optic communication that convert electrical signals into light for data transmission," said Jia.