Growth and Characterization of Nanostructured Carbon Film Field Emitters

University Of North Texas, Denton TX

Investigators

Abstract

This project aims to grow and characterize nanostructured carbon films consisting of carbon nanotube and amorphous carbon films. Films will be grown by CVD (chemical vapor deposition). Structural and electronic properties will be studied as a function of growth conditions using atomic resolution ultra-high vacuum (UHV) scanning tunneling microscopy (STM), Raman spectroscopy, Auger spectroscopy, ultraviolet photoemission spectroscopy and x-ray photoemission spectroscopy. The turn-on field for field emission (FE), emission site density, electron energy distribution, and stability and lifetime of the FE current will also be measured. Effects of residual gases on FE properties will be studied in detail. For carbon nanotube and amorphous carbon films, growth conditions resulting in optimum tube and asperity density, respectively, will be assessed for FPD applications. Such films have potential techno-logical applications as cold cathode electron emitters in flat panel displays (FPDs), miniature micro-wave sources, highly collimated electron sources and vacuum microelectronics. Using UHV STM, the effects of adsorbates on the structural and electronic properties of the caps of individual carbon nano-tubes will be studied. UHV STM will also be used to study structural and electronic properties of ad-sorbates that induce negative electron affinity in diamond such as hydrogen, Ti and Cs. The FE proper-ties of carbon nanotube and amorphous carbon films will be compared with those of diamond films and diamond-coated Mo microtips to determine the best material for FE applications. %%% The project addresses basic research issues in a topical area of materials science with high technologi-cal relevance. Advanced characterization techniques allow greater understanding and control of ele-mentary processes which will allow advances in fundamental materials science and technology. The basic knowledge and understanding gained from the research is expected to contribute to flat panel dis-play, and related applications of electronic and photonic materials. An important feature of the pro-gram is the integration of research and education through the training of students in a fundamentally and technologically significant area. ***