Study on Enhanced Electron Field Emission Properties of Graphene Quantum Dots Synthesized by Pulsed LASER Ablation

Graphene quantum dots (GQDs) and Nitrogen doped graphene quantum dots (N-GQDs) were synthesized by Pulsed LASER Ablation method. The nanostructure and chemical composition of the GQDs were analyzed by means of TEM, HRTEM, Raman, XPS, and FT-IR spectra. Field emission is a quantum mechanical phenomenon where electrons tunnel from the cathode to the anode through vacuum upon an applied electric field. So far field emission properties of two-dimensional (graphene) and one-dimensional (CNT) carbon nanostructures have been extensively studied. For the first time, to the best of our knowledge, the field emission behavior of GQDs and N-GQDs, deposited on n-Si (100) substrates, is studied. As a candidate of cold cathode, the GQDs display good field emission performance. The Field emission properties of GQDs and N-GQDs were studied by measuring turn-on field (<i>E</i>) and field enhancement factor β. The results show that nitrogen doping improved the field emission properties of GQDs by reducing turn-on field from 13.1V/μm (GQDs) to 7.9 V/μm (N-GQDs) and enhancing the field enhancement factor β from 1427(GQDs) to 2511(N-GQDs). The field emission behavior of pristine GQDs and N-GQDs is explained in terms of change in the effective microstructure as well as a reduction in the work function as probed by measured characterizations. The enhanced emission properties of N-GQDs are mainly attributed to the upshifting of fermi energy level and defects produced as a result of Nitrogen doping. The good emission performance of the GQDs field emitters suggests promising applications in next generation vacuum micro and nano electronic devices<br/><br/>&lt;quillbot-extension-portal&gt;&lt;/quillbot-extension-portal&gt;