Nanocone-Shaped Carbon Nanotubes Field-Emitter Array Fabricated by Laser Ablation
Jiuzhou Zhao, Zhenjun Li, Matthew T. Cole, Aiwei Wang, Xiangdong Guo, Xinchuan Liu, Wei Lyu, Hanchao Teng, Yunpeng Qv, Guanjiang Liu, Ke Chen, Shenghan Zhou, Jianfeng Xiao, Yi Li, Chi Li, Qing Dai
Abstract
The nanocone-shaped carbon nanotubes field-emitter array (NCNA) is a near-ideal field-emitter array that combines the advantages of geometry and material. In contrast to previous methods of field-emitter array, laser ablation is a low-cost and clean method that does not require any photolithography or wet chemistry. However, nanocone shapes are hard to achieve through laser ablation due to the micrometer-scale focusing spot. Here, we develop an ultraviolet (UV) laser beam patterning technique that is capable of reliably realizing NCNA with a cone-tip radius of ≈300 nm, utilizing optimized beam focusing and unique carbon nanotube–light interaction properties. The patterned array provided smaller turn-on fields (reduced from 2.6 to 1.6 V/μm) in emitters and supported a higher (increased from 10 to 140 mA/cm2) and more stable emission than their unpatterned counterparts. The present technique may be widely applied in the fabrication of high-performance CNTs field-emitter arrays.