Light responsivity of 2D materials enhanced using new method

Researchers have developed a promising new approach to modifying the light absorption and stretchability of atomically thin 2D materials.

A team from the University of Illinois College of Engineering have discovered that arranging 2D materials into 3D crumpled structures can increase the areal density of substances such as graphene, which consists of hexagonally bonded carbon atoms.

With a continuously undulating 3D surface, the crumpled structure yields higher optical absorption per unit area, thereby improving photoresponsivity. This effect can be achieved by surface topographic engineering using only mechanical strain.

Currently, graphene is seen as a promising material for photodetectors due to its broadband absorption, high carrier mobility and mechanical flexibility. However, its low optical absorptivity means that such studies have focused on hybrid systems, which require a complicated integration process.

It is thought that this flexible new approach will aid the future development of wearable technology and integrated biomedical optical sensing technology.

SungWoo Nam, an assistant professor of mechanical science and engineering at Illinois, said: "Increasing graphene's low light absorption in visible range is an important prerequisite for its broad potential applications in photonics and sensing."