Zhang Qin, Zhang Siyuan, Sperling Brent A, Nguyen Nhan V
Theiss Research, La Jolla, CA, USA.
Nanoscale Device Characterization Division, National Institute of Standards and Technology, Gaithersburg, MD, USA.
J Electron Mater. 2019 Oct;48(10). doi: 10.1007/s11664-019-07396-z.
The electron energy band alignment of the monolayer MoSe/oxide/Si system is characterized by internal photoemission spectroscopy, where the oxide is AlO or SiO. Raman and photoluminescence spectroscopic measurements confirm the high quality of monolayer MoSe exfoliated with gold film as medium. At the oxide flat-band condition, the band offset from the monolayer MoSe valence band maximum to the AlO and SiO conduction band minimum are measured to be (4.10 ± 0.05) eV and (4.80 ± 0.05) eV, respectively. By referencing the recently reported band gap value of 2.18 eV for monolayer MoSe, we obtain the electron affinity of monolayer MoSe to be (3.8 ± 0.1) eV on AlO/Si and (3.5 ± 0.1) eV on SiO/Si. It is believed that the results from this study will help accelerate the design of electronic and optoelectronic devices that employ this class of two-dimensional materials.
通过内部光发射光谱对单层MoSe/氧化物/Si系统的电子能带排列进行了表征，其中氧化物为AlO或SiO。拉曼光谱和光致发光光谱测量证实了以金膜为介质剥落的高质量单层MoSe。在氧化物平带条件下，测得从单层MoSe价带最大值到AlO和SiO导带最小值的带隙分别为(4.10±0.05) eV和(4.80±0.05) eV。通过参考最近报道的单层MoSe的带隙值2.18 eV，我们得出单层MoSe在AlO/Si上的电子亲和能为(3.8±0.1) eV，在SiO/Si上为(3.5±0.1) eV。相信这项研究的结果将有助于加速采用这类二维材料的电子和光电器件的设计。
