Cui Zhen, Wang Xia, Li Enling, Ding Yingchun, Sun Changlong, Sun Minglei
School of Automation and Information Engineering, Xi'an University of Technology, Xi'an, 710048, People's Republic of China.
Department of Radiology, Affiliated Hospital of Yan'an University, Yan'an, 716000, People's Republic of China.
Nanoscale Res Lett. 2018 Jul 11;13(1):207. doi: 10.1186/s11671-018-2625-z.
The electronic and optical properties of alkali-metal-adsorbed graphene-like gallium nitride (g-GaN) have been investigated using density functional theory. The results denote that alkali-metal-adsorbed g-GaN systems are stable compounds, with the most stable adsorption site being the center of the hexagonal ring. In addition, because of charge transfer from the alkali-metal atom to the host, the g-GaN layer shows clear n-type doping behavior. The adsorption of alkali metal atoms on g-GaN occurs via chemisorption. More importantly, the work function of g-GaN is substantially reduced following the adsorption of alkali-metal atoms. Specifically, the Cs-adsorbed g-GaN system shows an ultralow work function of 0.84 eV, which has great potential application in field-emission devices. In addition, the alkali-metal adsorption can lead to an increase in the static dielectric constant and extend the absorption spectrum of g-GaN.
利用密度泛函理论研究了碱金属吸附的类石墨烯氮化镓（g-GaN）的电子和光学性质。结果表明，碱金属吸附的g-GaN体系是稳定的化合物，最稳定的吸附位点是六元环的中心。此外，由于碱金属原子向主体的电荷转移，g-GaN层表现出明显的n型掺杂行为。碱金属原子在g-GaN上的吸附是通过化学吸附发生的。更重要的是，碱金属原子吸附后，g-GaN的功函数大幅降低。具体而言，Cs吸附的g-GaN体系表现出0.84 eV的超低功函数，在场发射器件中具有巨大的潜在应用。此外，碱金属吸附会导致g-GaN的静态介电常数增加，并扩展其吸收光谱。
