Abstract:The high-density carbon nanotubes (CNTs) are synthesized on Fe/Si substrate in the mixture of acetylene and hydrogen gas by radio frequency plasma enhanced chemical vapor deposition (RF-PECVD) method. The effects of substrate temperature on the growth of CNTs are studied by scanning electron microscopy (SEM), transmission electron microscopy (TEM) and Raman spectroscopy. The quality of CNTs is improved considerably by increasing the substrate temperature while the beam density is increased and graphitization degree (I D/I G) is enhanced. The best aligned CNTs are prepared at 750 °C, the beam D density is about 1.6 × 103/μm2, and I D/I G is about 0.93. Temperature influence is also discussed.