Alloy engineering of electronic and optical properties of tetragonal monolayer zinc chalcogenides

作者：Zhou, Jia; Wu, Xiaohong^*

来源：Journal of Alloys and Compounds, 2017, 695: 1392-1396.

DOI：10.1016/j.jallcom.2016.10.264

• Two-dimensional materials
• First-principles calculations
• Zinc chalcogenides
• Alloy
• Optical absorption
• Water splitting

Alloying has been widely applied for band gap engineering of semiconductors, as the band gap of an alloy can be continually tuned as a function of alloy concentration. Recently, the three-atom-thick tetragonal ZnSe and ZnS monolayers demonstrate a strong quantum confinement effect by showing a large enhancement of band gap compared to their zinc blende (ZB) bulk phases. In this study, we are aiming to investigate the electronic and optical properties of various tetragonal alloy ZnSxSe1-x monolayers based upon first-principles calculations. It is found that these alloy ZnSxSe1-x monolayers are all direct band gap semiconductors with tunable band gaps, plausible for visible-light-driven water splitting. It is suggested by theoretical optical absorbance calculations that alloy ZnS0.375Se0.625 monolayer has a higher absorption performance than pristine ZnSe and ZnS monolayers under certain wavelength within the visible light region. Our results open a new avenue for the future alloy engineering of the tetragonal ZnSe and ZnS monolayers for a wealth of potential optoelectronic applications.

• 出版日期2017-2-25
• 单位哈尔滨工业大学