Li Jun, Yan Xingbin, Gou Gaoyang, Wang Zhao, Chen Jiangtao
Laboratory of Clean Energy Chemistry and Materials, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000, China.
Phys Chem Chem Phys. 2014 Feb 7;16(5):1850-5. doi: 10.1039/c3cp53106f.
We study the effect of different gas adsorbates (N2, O2, and CO2) on the field emission (FE) properties of graphene film. Our experimental measurements show that, except for N2, adsorption of O2 and CO2 reduces the FE current of the graphene film. Moreover, the measured FE hysteresis loop is almost quenched after adsorbing O2 or CO2. The ab initio calculations quantify the experimental results by predicting a larger work function and smaller FE current for the graphene system after O2 or CO2 adsorption. In contrast, the change of FE properties in N2 adsorbed graphene is negligible. A "depolarization electric field model" is then proposed to explain the observed FE hysteresis behavior.
我们研究了不同气体吸附质（N₂、O₂和CO₂）对石墨烯薄膜场发射（FE）特性的影响。我们的实验测量表明，除了N₂之外，O₂和CO₂的吸附会降低石墨烯薄膜的场发射电流。此外，在吸附O₂或CO₂后，测得的场发射滞后回线几乎消失。从头算计算通过预测O₂或CO₂吸附后石墨烯体系具有更大的功函数和更小的场发射电流，对实验结果进行了量化。相比之下，N₂吸附的石墨烯中场发射特性的变化可以忽略不计。然后提出了一个“去极化电场模型”来解释观察到的场发射滞后行为。
