Ar Microwave Plasma Treatment of Carbon Nanotubes Film by Electrophoretic Deposition

The carbon nanotubes (CNTs) film was prepared on Si substrate by electrophoretic depo- sition (EPD) and treated by Ar microwave plasma.The microstructure and field emission properties of the as-prepared CNTs films before and after treatment were investigated.High-resolution transmission electron microscope (HRTEM) and Raman spectroscope reveal the microstructural changes of CNTs after the plasma treatment as evidence of the appearance of a large amount of structural defects,the sticking with nanometer size andneedle-liketips.The field emission measurements indicate that the turn on electric field is increased slightly after treatment.The sample treated by Ar plasma for 10min shows the best field emission J-E property.Compared to that of untreated sample,the threshold field of the CNTs film treated for 10min decreases from 3.12V/μm to 2.54V/μm.And after plasma treatment,the emission current density at applied electric field of 3.3V/μm increase from 18.4mA/cm~2 to 60.7mA/cm~2.The mechanism of variation of field emission properties after plasma treatment is discussed.