Work function variation of monolayer MoS2 by nitrogen-doping
Work function variation of monolayer MoS2 by nitrogen-doping
复制标题
氮掺杂单层MoS2功函数变化
DOI：
10.1063/1.5038602
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发表时间：
2018-07-23
影响因子：
4
通讯作者：
Luo, Xingfang
中科院分区：
文献类型：
--
作者：
Hu, Ce;Yuan, Cailei;Luo, Xingfang
利用高衬底温度和超高真空生长条件，采用L激光分子束外延技术获得了具有大量硫空位的单层MoS_2薄膜。本征硫空位为通过氮掺杂改变单层MoS_2薄膜功函数提供了极好的机会。在氮气环境中快速热退火的基础上，实现了L分子束外延合成的MoS_2单层薄膜中氮原子的面内掺杂。用拉曼光谱和光致发光光谱对生长的和掺氮的单层MoS_2薄膜进行了表征。根据X射线光电子能谱的结果，紫外光电子能谱研究表明，共价氮掺杂使单层MoS_2薄膜的功函数增加了0.29 eV。用第一性原理计算进一步从理论上处理了单层MoS_2的氮掺杂问题。理论计算和实验验证表明，氮是一种很有前途的单层MoS_2功函数变化的面内杂原子掺杂剂。
Monolayer MoS2 films with substantial sulfur vacancies are obtained using the laser molecular beam epitaxy (L-MBE) technique benefitted by high substrate temperature and ultrahigh vacuum growth conditions. The intrinsic sulfur vacancies present an excellent opportunity for varying the work function of monolayer MoS2 films by nitrogen doping. The in-plane doping of nitrogen atoms on L-MBE-synthesized monolayer MoS2 films is realized on the basis of rapid thermal annealing in a nitrogen environment. The as-grown and nitrogen-doped monolayer MoS2 films are evaluated by using Raman and photoluminescence spectroscopies. In accordance with the X-ray photoelectron spectroscopy results, the ultraviolet photoelectron spectroscopy investigation shows that the work function of the monolayer MoS2 films increases by 0.29 eV after covalent nitrogen doping. Nitrogen doping on monolayer MoS2 is further treated theoretically using first-principles calculations. Based on theoretical calculations and experimental validations, it is illustrated that nitrogen is a promising in-plane heteroatom dopant for work function variation of monolayer MoS2.