Hyderabad: A team from the University of Hyderabad (UoH), and the Indian Institute of Technology Hyderabad (IITH) has been granted a patent for fabricating one or more layered TMDC material using Bessel beam femtosecond laser ablation.
The patent introduces a new method to mass-produce high technology, microscopic materials, called transition metal dichalcogenide (TMDC) nanosheets, overcoming the nanotechnology size-confinement challenge, the University of Hyderabad said in a release.
The inventors behind this pioneering innovation are Dr Sai Santosh Kumar Raavi (IITH), Dr Challa Rajendra Kumar (IITH), Dr Moram Sree Satya Bharati (IITH/UoH), and Prof Soma Venugopal Rao (UoH).
TMDCs are a class of two-dimensional (2D) materials that, due to their exceptional optical, electronic, and mechanical properties, have taken the electronics world by storm. While bulk TMDC contains strong covalent bonds within individual layers, these layers are stacked together by weak van der Waals forces.
While traditionally isolating single, or a few-layered nanosheets requires breaking the weak interlayer forces, it has been achieved through other methods, including mechanical exfoliation (the Scotch-tape method), chemical exfoliation, or chemical vapor deposition (CVD). However, these processes are heavily restricted. They are either incredibly time-consuming, chemically intensive, high-cost, or difficult to scale due to size-confinement limitations.
With the newly patented method, these traditional constraints are bypassed by deploying ultra-short, high-precision laser technology. The technique involves shaping a femtosecond (incredibly brief unit of time) laser beam into a specialised Bessel beam profile and focusing it directly onto a synthesised TMDC pellet.
By firing one or more ultra-fast laser pulses at the target, the intense energy precisely breaks the weak van der Waals forces holding the layers together without damaging the chemical structure of the material itself. This localised laser removal produces single, or multi-layered TMDC nanosheets instantaneously, creating a path for industrial-scale manufacturing.
