The electric field emission behavior of vertically aligned few-layer graphene was studied in a parallel plate-type setup. Few-layer graphene was synthesized in the absence of any metallic catalyst by microwave plasma enhanced chemical vapor deposition with gas mixtures of methane and hydrogen. The deposit consists of nanostructures that are several micrometers wide, highly crystalline stacks of four to six atomic layers of graphene, aligned vertically to the substrate surface in a high density network. The few-layer graphene is found to be a good field emitter, characterized by turn-on fields as low as 1 V/μm and field amplification factors up to several thousands. We observe a clear dependence of the few-layer graphene field emission behavior on the synthesis parameters: Hydrogen is identified as an efficient etchant to improve field emission, and samples grown on titanium show lower turn-on field values and higher amplification factors when compared to samples grown on silicon.
展开▼
机译:在平行板型设置中研究了垂直排列的多层石墨烯的电场发射行为。在不存在任何金属催化剂的情况下,通过微波等离子体增强的化学气相沉积以及甲烷和氢气的混合气体,合成了几层石墨烯。该沉积物由几微米宽的纳米结构,四到六层石墨烯原子层的高度结晶堆叠组成,并在高密度网络中垂直于基板表面排列。人们发现,几层石墨烯是一种良好的场致发射器,其特征在于导通场低至1 V /μm,场放大因子高达数千。我们观察到了几层石墨烯场发射行为对合成参数的明显依赖性:氢被认为是一种改善场发射的有效蚀刻剂,与钛相比,在钛上生长的样品显示出更低的开启场值和更高的放大系数。样品生长在硅上。
展开▼