Enhancing the performance of carbon nanotubes in field emission through thermomechanical stretching

Carbon nanotubes (CNTs) are recognized as excellent field-emitting materials due to their superior electrical properties, which have significant advantages in advanced vacuum electronics. This study explores the field emission characteristics in CNTs enhanced by thermomechanical tensile processes. In this study, molecular simulations were performed using LAMMPS software to observe the structural changes of various carbon nanotubes during thermomechanical processing. In addition, COMSOL Multiphysics was used to analyze the field emission performance of the CNT after fracture. The results show that the thermomechanical stretching process contributes to the formation of sharp fractured surfaces during the fracture of single-walled carbon nanotubes (SWCNTs), thereby significantly improving the field emission performance with a maximum surface electric field increase of up to 3.58-fold. Since the long-arm tip of the CNT array is pulled out, its field emission performance is also significantly enhanced, with a maximum increase of 4.21-fold. However, this enhancement tends to decrease as the diameter of the carbon nanotubes or the size of the array increases. The study concludes that thermomechanical stretching can effectively improve the field emission performance of small-diameter carbon nanotubes and arrays, providing a theoretical basis for designing carbon-based nanoelectron emission devices.