▎ 摘 要
A facile approach is used to grow sharp folded and wrinkled graphene structures by laser ablation process. The laser-graphite target interaction mechanism and effect of substrate temperature variation (400 degrees C and 700 degrees C) on the growth structure of graphene is studied. The low solubility of carbon in Cu helps in the deposition of graphene flakes by self-limiting process. High resolution transmission electron microscopy and Raman spectroscopy are utilized to confirm the crystalline structure of graphene at higher temperatures. These exotic structures are further studied for their electron field emission characteristics after transferring over Si/SiO2 substrates. The sharp folded graphene structures (turn-on field 1.4 V/mu m) displayed enhanced electron field emission properties in comparison to wrinkled graphene (turn-on field 2.0 V/mu m). The obtained wrinkled graphene structure is extremely suitable for field emission applications. This work presents an efficient technique to grow different graphene structures using laser ablation process that can act as potential candidates for future field emission devices. (C) 2014 Elsevier Ltd. All rights reserved.