Ultrathin and Flat Layer Black Phosphorus Fabricated by Reactive Oxygen and Water Rinse

作者：Kwon Hyuksang; Seo Sung Won; Kim Tae Gun; Lee Eun Seong; Lanh Phung Thi; Yang Sena; Ryu Sunmin; Kim Jeong Won

来源：ACS Nano, 2016, 10(9): 8723-8731.

DOI：10.1021/acsnano.6b04194

• phosphorene (black phosphorus)
• ozone
• etching
• water
• protective layer

Ultrathin black phosphorus (BP) is one of the promising two-dimensional (2D) materials for future optoelectronic devices. Its chemical instability in ambient conditions and lack of a bottom-up approach for its synthesis necessitate efficient etching methods that generate BP films of designed thickness with stable and high-quality surfaces. Herein, reporting a photochemical etching method, we demonstrate a controlled layer-by-layer thinning of thick BP films down to a few layers or a single layer and confirm their Raman and photoluminescence characteristics. Ozone molecules generated by O-2 photolysis oxidize BP, forming P2O5-like oxides. When the resulting phosphorus oxides are removed by water, the surface of BP with preset thickness is highly flat and self-protective by surface oxygen functional groups. This method provides a fabrication strategy of BP and possibly other 2D semiconductors with band gaps tuned by their thickness.

• 出版日期2016-9