Improved field electron emission from SiC assisted carbon nanorod/nanotube heterostructured arrays by using energetic Si ion irradiation

Field electron emission characteristics of energetic silicon ion irradiated carbon nanotube arrays were investigated. SEM, TEM, Raman, XPS and photoelectron spectrometry characterizations were done for comparison before and after the silicon ion irradiation. Carbon nanorod/nanotube heterostructure is obtained and SiC compound is formed in the carbon nanotubes after the silicon ion irradiation. Silicon ion irradiated carbon nanotube arrays with an irradiation dose of 8.6 × 1016 ions/cm2 show excellent field emission properties, with low turn-on and threshold fields of 0.726 and 1.164 V/μm, respectively, which are far better than that of the original and the silicon ion irradiated carbon nanotube arrays with other irradiation doses. We attribute the main reason for this field emission enhancement to the change of microstructures of carbon nanotubes, which directly influences the number of emission sites during field emission and additionally, the formation of low work function SiC compound. However, with further increasing the irradiation dose, the field emission characteristics of the carbon nanotube arrays deteriorate for the decrease of emission sites induced by severe structural damage. Furthermore, the silicon ion irradiated carbon nanotube arrays with an irradiation dose of 8.6 × 1016 ions/cm2 present far better stability than the original carbon nanotubes, providing a possibility for the application of high-performance field emission devices.

► Precisely controlled Si ion irradiation on CNTAs
► Relationship between the microstructures and the irradiation doses of CNTAs
► Formation of SiC compound assisted carbon nanorod/nanotube heterostructure