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A) FIELD EMISSION STUDIES ON CARBON NANOTUBES and CuO NANOWIRES

Speaker: Mr Zhu Yanwu (NUSNNI Research Scholar)  

Abstract
 We have exposed aligned multi-wall carbon nanotube (MWCNT) films to CF4 plasma from Reactive Ion Etching (RIE) system and studied the corresponding dependence of the field esmission (FE) properties of the films on the time of exposure. It is found that that after 2 minutes of plasma treatment the emission currents were enhanced compared with as grown CNTs; however, extended treatment over 2 minutes degraded FE properties of the film. With the help of Characterizations it is found that the FE enhancement could be attributed to favorable surface morphologies, open-ended structures and a large number of defects in the aligned CNT films.

At the same time, we have used a simple method of direct heating of bulk copper plates in air to synthesize oriented CuO nanowire films on a large scale. The length and density of nanowires could be controlled by growth temperature and growth time. FE measurement of CuO nanowire films show that they have a low turn-on field of 3.5 ~ 4.5 V/mm and a large current density of 0.45 mA/cm2 under an applied field of about 7 V/mm. Verified with finite element calculation, the work function of oriented CuO nanowire films was estimated to be 2.6 ~ 2.8 eV. Moreover, laser-enhanced FE properties have been observed in our experiments. By direct incidence of green (532nm) and infrared (1064nm) laser beams, the emission current was largely improved. The enhancement degree was related to the applied field, laser power, laser wavelength and shinning time.


B) OPTICAL LIMITING and FIELD EMISSION STUDIES of CARBON NANOTUBES

 Speaker: Mr Gohel Amarsinh, Brandon (PG Student, Dept of Physics)

Abstract

 Not available for viewing (In the process of filing a patent)
 


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