Plasma-assisted fabrication of monolayer phosphorene and its Raman characterization
Mechanical cleavage, monolayer phosphorene, two-dimensional semiconductor, plasma thinning, optical contrast, Raman spectroscopy
There have been continuous efforts to seek novel functional two-dimensional semiconductors with high performance for future applications in nanoelectronics and optoelectronics. In this work, we introduce a successful experimental approach to fabricate monolayer phosphorene by mechanical cleavage and a subsequent Ar+ plasma thinning process. The thickness of phosphorene is unambiguously determined by optical contrast spectra combined with atomic force microscopy (AFM). Raman spectroscopy is used to characterize the pristine and plasma-treated samples. The Raman frequency of the A2g mode stiffens, and the intensity ratio of A2g to A1g modes shows a monotonic discrete increase with the decrease of phosphorene thickness down to a monolayer. All those phenomena can be used to identify the thickness of this novel two-dimensional semiconductor. This work on monolayer phosphorene fabrication and thickness determination will facilitate future research on phosphorene.
Tsinghua University Press
Wanglin Lu,Haiyan Nan,Jinhua Hong,Yuming Chen,Chen Zhu,Zheng Liang,Xiangyang Ma,Zhenhua Ni,Chuanhong Jin,Ze Zhang, Plasma-assisted fabrication of monolayer phosphorene and its Raman characterization. NanoRes.2014, 7(6): 853–859