Field Emission Properties of Ball-Like Nano-Carbon Thin Films Deposited on Mo Films with Accidented Topography  

作　　者：王隆洋 王小平 王丽军 张雷 

机构地区：[1]College of Science, University of Shanghai for Science and Technology, Shanghai 200093

出　　处：《Chinese Physics Letters》2008年第11期4154-4157,共4页中国物理快报（英文版）

摘　　要：Ball-like nano-earbon thin films （BNCTs） are grown on Mo layers by microwave plasma chemical vapour deposition （MPCVD） system. The Mo layers are deposited on ceramic substrates by electron beam deposition method and are pretreated by ultrasonically scratching. The optimization effects of ultrasonically scratching pretreatment on the surface micro-structures of carbon films are studied. It is found from field-emission scanning electron microscope （FE-SEM） images and Raman spectra that the surface structures of the carbon films deposited on Mo pretreated are improved, which are composed of highly uniform nano-structured carbon balls with considerable disorder structures. Field emission （FE） measurements are carried out using a diode structure. The experimental results indicate that the BNCTs exhibit good FE properties, which have the turn on field of 1.56 V/μm, and the current density of 1.0mA/cm^2 at electric field of 4.0 V/μm, the uniformly distributed emission site density from a broad well-proportioned emission area of 4 cm^2 are also obtained. Linearity is observed in Fowler Nordheim （F N） plots in higher field region, and the possible emission mechanism of BNCTs is discussed.Ball-like nano-earbon thin films （BNCTs） are grown on Mo layers by microwave plasma chemical vapour deposition （MPCVD） system. The Mo layers are deposited on ceramic substrates by electron beam deposition method and are pretreated by ultrasonically scratching. The optimization effects of ultrasonically scratching pretreatment on the surface micro-structures of carbon films are studied. It is found from field-emission scanning electron microscope （FE-SEM） images and Raman spectra that the surface structures of the carbon films deposited on Mo pretreated are improved, which are composed of highly uniform nano-structured carbon balls with considerable disorder structures. Field emission （FE） measurements are carried out using a diode structure. The experimental results indicate that the BNCTs exhibit good FE properties, which have the turn on field of 1.56 V/μm, and the current density of 1.0mA/cm^2 at electric field of 4.0 V/μm, the uniformly distributed emission site density from a broad well-proportioned emission area of 4 cm^2 are also obtained. Linearity is observed in Fowler Nordheim （F N） plots in higher field region, and the possible emission mechanism of BNCTs is discussed.

关 键 词：the power-law exponents precipitation durative abrupt precipitation change 

分 类 号：O484[理学—固体物理]