Aligned carbon nanotube (CNRT) films exhibit excellent electron emission properties at very low fields. This has been attributed to the high aspect ratio of CNTs, I.e. Their emitting surface can have high local field ...Aligned carbon nanotube (CNRT) films exhibit excellent electron emission properties at very low fields. This has been attributed to the high aspect ratio of CNTs, I.e. Their emitting surface can have high local field due to geometrical enhancement. It is found that a new mechanism can be responsible for the enhancement of the local field on the emitting surface of CNTs. This results from the space charge in the vacuum gap, which is readily generated due to the high emission current density of CNTs. Details are given of both experimental and theoretical studies of this effect. The mechanism also accounts for the distinct nonlinearity in Fowler-Nordheim plots often observed with CNTs. The implication of the technical application of our findings is also included.展开更多
Significant field emission has been observed from thin(<1000Å)amorphous-carbon-nitride(a-CN)films.X-ray photoelectron spectroscopy,infrared spectrometry,and UV-visible optical absorption spectrometry have been...Significant field emission has been observed from thin(<1000Å)amorphous-carbon-nitride(a-CN)films.X-ray photoelectron spectroscopy,infrared spectrometry,and UV-visible optical absorption spectrometry have been used to characterize the films.The field emission properties of the thin film have been studied by using a transparent anode imaging system.It is proposed that this class of films should be studied as candidates of coating material for cold cathode emitter,in order for one to benefit from their very high thermal conductivity and super hardness.展开更多
Stable cold-cathode electron emission at fields as low as 3 MV/m has been observed from two types of carbon-containing thin film of thickness in submicron scale,i.e.,non-doped fullerene C60 and amorphous diamond films...Stable cold-cathode electron emission at fields as low as 3 MV/m has been observed from two types of carbon-containing thin film of thickness in submicron scale,i.e.,non-doped fullerene C60 and amorphous diamond films.A transparent anode imaging technique was used to record the spatial distribution of individual sites and the total emission current-voltage characteristic of the films.It is found that supplemental measurements of optical spectra and electrical conductivity of the films can provide important evidence useful for understanding the differences in emission behaviour between two types of film.展开更多
基金Supported by the National Natural Science Foundation of China under Grant No.59525206the Education Ministry of China and the Higher Education Bureau,the Science and Technology Commission of Guangdong Province.
文摘Aligned carbon nanotube (CNRT) films exhibit excellent electron emission properties at very low fields. This has been attributed to the high aspect ratio of CNTs, I.e. Their emitting surface can have high local field due to geometrical enhancement. It is found that a new mechanism can be responsible for the enhancement of the local field on the emitting surface of CNTs. This results from the space charge in the vacuum gap, which is readily generated due to the high emission current density of CNTs. Details are given of both experimental and theoretical studies of this effect. The mechanism also accounts for the distinct nonlinearity in Fowler-Nordheim plots often observed with CNTs. The implication of the technical application of our findings is also included.
基金Supported by the National Natural Science Foundation for Outstanding Youth of China under Grant No.59525206the Higher Education Bureau of Guangdong Province.
文摘Significant field emission has been observed from thin(<1000Å)amorphous-carbon-nitride(a-CN)films.X-ray photoelectron spectroscopy,infrared spectrometry,and UV-visible optical absorption spectrometry have been used to characterize the films.The field emission properties of the thin film have been studied by using a transparent anode imaging system.It is proposed that this class of films should be studied as candidates of coating material for cold cathode emitter,in order for one to benefit from their very high thermal conductivity and super hardness.
基金Supported by the National Natural Science Foundation for Outstanding Youth of China under Grant No.59525206,a special grant from the Foundation of Key Disciplines of the Higher Education Bureau ofGuangdong Province.
文摘Stable cold-cathode electron emission at fields as low as 3 MV/m has been observed from two types of carbon-containing thin film of thickness in submicron scale,i.e.,non-doped fullerene C60 and amorphous diamond films.A transparent anode imaging technique was used to record the spatial distribution of individual sites and the total emission current-voltage characteristic of the films.It is found that supplemental measurements of optical spectra and electrical conductivity of the films can provide important evidence useful for understanding the differences in emission behaviour between two types of film.
