Thermionic electron emission from single carbon nanostructures and its applications in vacuum nanoelectronics
- PDF / 718,347 Bytes
- 7 Pages / 585 x 783 pts Page_size
- 57 Downloads / 185 Views
Introduction Many important electronic devices rely on electrons moving in a vacuum (e.g., x-ray tubes for health and security examination, microwave tubes for wireless communications and radar detection, and cathode-ray tubes for signal display); therefore, an electron source that generates free electrons in a vacuum is indispensable for devices called “vacuum electronic devices.” To date, most commercial vacuum electronic devices employ traditional thermionic electron sources where electrons are evaporated into a vacuum through heating. Because of the bulky size, slow temporal response, and high-energy dissipation of traditional thermionic electron sources, vacuum electronic devices usually have large volumes, slow switching speeds, and high power consumption. To overcome these limitations, efforts have been made since the 1960s to scale down electron sources and vacuum electronic devices to the microscale and even nanoscale by using micro-/ nanofabrication technologies,1–6 thus creating a new research field called vacuum micro-/nanoelectronics. Many novel applications (i.e., microscale vacuum transistors,7,8 flat-panel
displays,9,10 and compact x-ray tubes11) have emerged in the field. In this context, nanoscale electron sources with high electron-emitting performances are highly desired since they work at the heart of nanoscale vacuum electronic devices. Because of their natural nanoscale size and cold-emission character, field-emission electron sources, where electrons are drawn out from a sharp nanoscale tip by an intense electric field through the quantum tunneling effect, have prevailed in vacuum nanoelectronics since the pioneering work of Spindt in 1968.1 While great success has been achieved for fieldemission sources, they have encountered problems of poor controllability and stability, poor uniformity in source arrays, high working voltage, and ultrahigh vacuum requirement. It is therefore important to look for new nanoscale electron sources that can avoid the previously mentioned problems. Thermionic electron emission from carbon filaments in incandescent lamps was observed for the first time by Edison.12 This reminds us that carbon nanotubes (CNTs) and graphene, which can be considered as nanoscale carbon filaments, can work as nanoscale thermionic electron sources because of their excellent
Xianlong Wei, Department of Electronics, Key Laboratory for the Physics and Chemistry of Nanodevices, Peking University, China; [email protected] Qing Chen, Department of Electronics, Key Laboratory for the Physics and Chemistry of Nanodevices, Peking University, China; [email protected] Lian-Mao Peng, Department of Electronics, Key Laboratory for the Physics and Chemistry of Nanodevices, Peking University, China; [email protected] doi:10.1557/mrs.2017.145
• VOLUME Core • www.mrs.org/bulletin 2017 Materials Research Society MRS BULLETIN 42 • terms JULY 2017 Downloaded© from https://www.cambridge.org/core. University of Pennsylvania Libraries, on 17 Jul 2017 at 07:19:41, subject to the Cambridge of use, available at https
Data Loading...
