Breakdown of Richardson's Law in Electron Emission from Individual Self-Joule-Heated Carbon Nanotubes
نویسندگان
چکیده
Probing the validity of classical macroscopic physical laws at the nanoscale is important for nanoscience research. Herein, we report on experimental evidence that electron emission from individual hot carbon nanotubes (CNTs) heated by self-Joule-heating does not obey Richardson's law of thermionic emission. By using an in-situ multi-probe measurement technique, electron emission density (J) and temperature (T) of individual self-Joule-heated CNTs are simultaneously determined. Experimental ln(J/T(2)) - 1/T plots are found to exhibit an upward bending feature deviating from the straight lines in Richardson plots, and the measured electron emission density is more than one order of magnitude higher than that predicted by Richardson's law. The breakdown of Richardson's law implies a much better electron emission performance of individual CNTs as compared to their macroscopic allotropes and clusters, and the need of new theoretical descriptions of electron emission from individual low-dimensional nanostructures.
منابع مشابه
Field emission and anode etching during formation of length-controlled nanogaps in electrical breakdown of horizontally aligned single-walled carbon nanotubes.
We observe field emission between nanogaps and voltage-driven gap extension of single-walled carbon nanotubes (SWNTs) on substrates during the electrical breakdown process. Experimental results show that the gap size is dependent on the applied voltage and humidity, which indicates high controllability of the gap size by appropriate adjustment of these parameters in accordance with the applicat...
متن کاملJoule heating in single-walled carbon nanotubes
Joule heating in single-walled carbon nanotubes CNTs using a quantum mechanical approach is presented in this paper. The modeling is based on the energy transfer between the electrons and both acoustic and optical phonons. In this formulation, only the knowledge of the full energy dispersion relation, phonon dispersion relation, and the electron-phonon coupling potential is required for the cal...
متن کاملThe role of electrical and thermal contact resistance for Joule breakdown of single-wall carbon nanotubes.
Several data sets for the electrical breakdown in air of single-wall carbon nanotubes (SWNTs) on insulating substrates are collected and analyzed. A universal scaling of the Joule breakdown power with nanotube length is found, which appears to be independent of the substrate thermal properties of their thickness. This suggests that the thermal resistances at SWNT-insulator and at SWNT-electrode...
متن کاملField emission of individual carbon nanotubes in the scanning electron microscope.
The field emission of individual multiwall carbon nanotubes grown by chemical vapor deposition was measured in a scanning electron microscope. By using a sharp anode, we were able to select one nanotube for measurements in carefully controlled conditions. Single nanotubes follow the Fowler-Nordheim law, and the dependence of the field enhancement with interelectrode distance and nanotube radius...
متن کاملSelf-aligned Cu etch mask for individually addressable metallic and semiconducting carbon nanotubes.
Two means to achieve high yield of individually addressable single-walled carbon nanotubes (CNTs) are developed and examined. The first approach matches the effective channel width and the density of horizontally aligned CNTs. This method can provide single CNT devices and also allows control over the average number of CNTs per channel. The second and a more deterministic approach uses self-ali...
متن کامل