Carbon Nanotubes as an Ultrafast Emitter with a Narrow Energy Spread at Optical Frequency. Issue 30 (6th June 2017)

• Record Type: Journal Article
• Authors: Li, Chi; Zhou, Xu; Zhai, Feng; Li, Zhenjun; Yao, Fengrui; Qiao, Ruixi; Chen, Ke; Cole, Matthew Thomas; Yu, Dapeng; Sun, Zhipei; Liu, Kaihui; Dai, Qing
• Is Part Of: Advanced materials. Volume 29:Issue 30(2017)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2017-06-06
• Subjects: carbon nanotubes -- electron sources -- field‐driven -- monochromatic -- ultrafast photoemission; Materials -- Periodicals; Chemical vapor deposition -- Periodicals; 620.11
• DOI: 10.1002/adma.201701580
• Languages: English
• ISSNs: 0935-9648

Abstract

Abstract : Ultrafast electron pulses, combined with laser‐pump and electron‐probe technologies, allow ultrafast dynamics to be characterized in materials. However, the pursuit of simultaneous ultimate spatial and temporal resolution of microscopy and spectroscopy is largely subdued by the low monochromaticity of the electron pulses and their poor phase synchronization to the optical excitation pulses. Field‐driven photoemission from metal tips provides high light‐phase synchronization, but suffers large electron energy spreads (3–100 eV) as driven by a long wavelength laser (>800 nm). Here, ultrafast electron emission from carbon nanotubes (≈1 nm radius) excited by a 410 nm femtosecond laser is realized in the field‐driven regime. In addition, the emitted electrons have great monochromaticity with energy spread as low as 0.25 eV. This great performance benefits from the extraordinarily high field enhancement and great stability of carbon nanotubes, superior to metal tips. The new nanotube‐based ultrafast electron source opens exciting prospects for extending current characterization to sub‐femtosecond temporal resolution as well as sub‐nanometer spatial resolution. Abstract : Field‐driven photoemission sources based on metal tips allow ultrafast characterization with ultimate spatio–temporal resolution, but suffer large energy spreads (>3 eV). Photoemission from carbon nanotubes excited by a 410 nm femtosecond laser is realized in the field‐driven regime with a 0.25 eV energy spread, which benefits from the high field enhancement and great stability of the carbon nanotubes.