Research on the preparation of amorphous diamond nanorod arrays and their excellent field emitting properties

Abstract

Amorphous diamond nanorod arrays with excellent field emitting have been fabricated firstly on the AAO template by the filtered cathodic arc plasma technique. Microscopic analysis has displayed that the nanorods are very uniformly distributed, and the density is very high up to ~10 9 cm −2 . The nanorod arrays are found to have an extremely low turn-on field of 0.16 V/μm, which is lower than other reported materials, and a highemission current density of 180 mA/cm 2 under an applied field of 2 V/μm can also be obtained. Scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), and filed emitting tester are employed to characterize the nanorod arrays. The field emission mechanism of the nanorod arrays is also discussed.Keywords: amorphous diamond nanorod arrays, magnetic filtered plasma, AAO, field electron emitting.During recent years, with the rapid development of IT and micro-electrics, the ultrathin, ultra-large display screen with low power consumption, has attracted more and more attention. As the core of devices, cathode materials are made much more demands in the vacuum microelectronic technology. So the materials with low power consumption, outstanding field emission properties and extreme stability are very important. To resolve the problem, many researchers have been making efforts. Diamonds as one of the broadband gap materials (such as c-BN, AlN, SiC, Al 2 O 3 and LiF, etc.) have attracted increasing attention [1][2][3][4][5][6][7][8][9][10] . All these materials have many merits such as excellent chemical, thermo stability, high melting point, thermal conductivity coefficient, small dielectric constant, high current carrier mobility ratio and high break-over voltage, especially, low electron affinity (EA). Some of them are negative electron affinity (NEA), which avails the field electron to emit. Recently, the threshold field of 3-40 V/μm for diamond film has been obtained by using chemical vapour deposition technology in the world. Some key problems have not been solved, including the reliability, stability, and uniformity of www.scichina.com www.springerlink.com Research on preparation of amorphous diamond nanorod arrays and field emitting properties 157 electron emission, which makes diamond films not be used in commercial applications.In the last decade, the field emission characteristics of diamond-like films had received extensive interests, because it was similar to diamond and easier to be fabricated compared with diamond films. From 1997 to 1998, Robertson and his co-workers [11][12][13][14] , who compared the field emission of diamond-like films with that of diamond films, indicated that for diamond possessing the surface negative electron affinity characteristics, the emission was mainly decided by the electronic conduction properties of contacted films; and without negative electron affinity, the emission of diamond-like film was mainly decided by surface barrier. Furthermore, he indicated that the surface electron affinity mainly depended on the atom-bonding cha...