Formation of freestanding two-dimensional carbon nanosheets from poly(phenylcarbyne) through pulsed laser ablation

Freestanding, two-dimensional (2D), amorphous carbon nanosheets (CNSs) were formed from a preceramic polymer, poly(phenylcarbyne), through laser ablation using a pulsed Nd:YAG laser. CNSs of several nanometers in thickness and micrometers in size were obtained. The polymer-to-carbon transition was investigated at different laser fluences and target-to-substrate distances. Three different phases, amorphous carbon, ultrathin amorphous CNSs, and thick carbon films, were obtained as the laser fluence increased. The pulsed-laser-induced formation of the 2D CNSs includes three steps: ablation, carbonization, and landing. This study reveals an existing route of forming freestanding 2D CNSs through pulsed laser ablation.