Quasi‐Monolayer Black Phosphorus with High Mobility and Air Stability |
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Authors: | Sherman Jun Rong Tan Ibrahim Abdelwahab Leiqiang Chu Sock Mui Poh Yanpeng Liu Jiong Lu Wei Chen Kian Ping Loh |
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Affiliation: | 1. Department of Chemistry, National University of Singapore, Singapore, Singapore;2. NUS Graduate School for Integrative Sciences and Engineering, National University of Singapore, Centre for Life Sciences, Singapore, Singapore;3. Centre for Advanced 2D Materials and Graphene Research Centre, National University of Singapore, Singapore, Singapore |
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Abstract: | Black phosphorus (BP) exhibits thickness‐dependent band gap and high electronic mobility. The chemical intercalation of BP with alkali metal has attracted attention recently due to the generation of universal superconductivity regardless of the type of alkali metals. However, both ultrathin BP, as well as alkali metal‐intercalated BP, are highly unstable and corrode rapidly under ambient conditions. This study demonstrates that alkali metal hydride intercalation decouples monolayer to few layers BP from the bulk BP, allowing an optical gap of ≈1.7 eV and an electronic gap of 1.98 eV to be measured by photoluminescence and electron energy loss spectroscopy at the intercalated regions. Raman and transport measurements confirm that chemically intercalated BP exhibits enhanced stability, while maintaining a high hole mobility of up to ≈800 cm2 V?1 s?1 and on/off ratio exceeding 103. The use of alkali metal hydrides as intercalants should be applicable to a wide range of layered 2D materials and pave the way for generating highly stable, quasi‐monolayer 2D materials. |
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Keywords: | alkali metal intercalation black phosphorus |
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