The group of Professor Peter Baum from the University of Constance studied two-dimensional materials that change their shape and their unique properties under the influence of a laser.
In the new work, the authors studied two-dimensional molecularly defined sheets, called MXenes.
By using laser pulses, the MXene can be switched multiple times between flat and wavy, opening up a wide range of possible applications.
MXenes are two-dimensional sheets of transition metal carbides or nitrides: they are arranged in single layers several atoms thick. This fine structure can only be obtained by exfoliating one material into many small layers.
Unlike most other single coat materials, MXene can be easily produced in large quantities thanks to the discovery of a scalable and irreversible chemical exfoliation method.
The chemical and physical properties of MXene are customizable depending on the choice of transition metal. Therefore, the material can be used for sensing, energy storage, light collection and even antibacterial effects.
In a new study, the authors improved the properties of MXene by using fast pulses of light that they directed at the material. As a result, they found that laser energy is transferred to the atomic lattice in record time – only 230 femtoseconds. The researchers also managed to control the orientation of nanowaves using laser polarization: this means that the material has optical memory at the nanoscale.
Moreover, if the laser is again pointed at the MXene, the material will again turn into a plane.