Structure and photoluminescence properties of carbon nanotip-vertical graphene nanohybrids

We report on the effective enhancement and tuning of photoluminescence (PL) by combining vertical graphene nanoflakes (VGs) and carbon nanotips (CNTPs). The VGs are grown on the vertical CNTPs by hot filament chemical vapor deposition in the methane environment, where the CNTPs are synthesized on silicon substrates by CH4-H-2-N-2 plasma-enhanced hot filament chemical vapor deposition. The results of field emission scanning electron microscopy, transmission electron microscopy, micro-Raman spectroscopy, and X-ray photoelectron spectroscopy indicate that the VGs can be grown on the CNTP and silicon substrate surfaces with the orientation perpendicular to the surfaces of CNTPs and silicon substrates. The PL properties of VG, CNTP, and CNTP-VG structures are studied using a 325 nm line of He-Cd laser as the excitation source. The PL results indicate that the PL of VGs is enhanced by the CNTPs due to the increasing density of PL emitters, while the PL properties of the nanohybrid system can be tuned. Furthermore, the potential applications of CNTP-VG structures in optoelectronic devices are analyzed. These results contribute to the design of functional graphene-based materials and the development of next-generation optoelectronic devices. (C) 2016 AIP Publishing LLC.