Quasi‐Monolayer Black Phosphorus with High Mobility and Air Stability. Issue 6 (3rd January 2018)

• Record Type: Journal Article
• Authors: Tan, Sherman Jun Rong; Abdelwahab, Ibrahim; Chu, Leiqiang; Poh, Sock Mui; Liu, Yanpeng; Lu, Jiong; Chen, Wei; Loh, Kian Ping
• Is Part Of: Advanced materials. Volume 30:Issue 6(2018)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2018-01-03
• Subjects: alkali metal intercalation -- black phosphorus; Materials -- Periodicals; Chemical vapor deposition -- Periodicals; 620.11
• DOI: 10.1002/adma.201704619
• Languages: English
• ISSNs: 0935-9648

Abstract

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 cm 2 V −1 s −1 and on/off ratio exceeding 10 3 . 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. Abstract : Stable quasi‐monolayer black phosphorus BP (optical gap of ≈1.7 eV and electronic gap of 1.98 eV) with high hole mobility of ≈800 cm 2 V −1 s −1 and on/off ratio exceeding 10 3 is presented. This is achieved through a two‐stage LiH intercalation of multilayer BP. This strategy extends the shelf life of alkali metal intercalated materials.