Liu Bin, Su Wan-Sheng, Wu Bi-Ru
School of Mathematics and Physics, Nanyang Institute of Technology, Nanyang 473004, China.
National Taiwan Science Education Center, Taipei 11165, Taiwan.
Nanomaterials (Basel). 2022 Nov 4;12(21):3898. doi: 10.3390/nano12213898.
Element doping is a universal way to improve the electronic and optical properties of two-dimensional (2D) materials. Here, we investigate the influence of group-ⅣA element (C, Si, Ge, Sn, and Pb) doping on the electronic and optical properties of the ZnS monolayer with a tetragonal phase by using first-principles calculations. The results indicate that the doping atoms tend to form tetrahedral structures with neighboring S atoms. In these doped models, the formation energies are all negative, indicating that the formation processes of the doped models will release energy. The formation energy is smallest for C-doped ZnS and gradually increases with the metallicity of the doping element. The doped ZnS monolayer retains a direct band gap, with this band gap changing little in other element doping cases. Moreover, intermediate states are observed that are induced by the sp hybridization from the doping atoms and S atoms. Such intermediate states expand the optical absorption range into the visible spectrum. Our findings provide an in-depth understanding of the electronic and optical properties of the ZnS monolayer and the associated doping structures, which is helpful for application in optoelectronic devices.
元素掺杂是改善二维（2D）材料电子和光学性质的一种通用方法。在此，我们通过第一性原理计算研究了ⅣA族元素（碳、硅、锗、锡和铅）掺杂对四方相硫化锌单层电子和光学性质的影响。结果表明，掺杂原子倾向于与相邻的硫原子形成四面体结构。在这些掺杂模型中，形成能均为负值，表明掺杂模型的形成过程会释放能量。碳掺杂硫化锌的形成能最小，并随着掺杂元素金属性的增强而逐渐增大。掺杂的硫化锌单层保持直接带隙，在其他元素掺杂情况下，该带隙变化不大。此外，观察到由掺杂原子和硫原子的sp杂化诱导产生的中间态。这些中间态将光吸收范围扩展到可见光谱。我们的研究结果深入了解了硫化锌单层的电子和光学性质以及相关的掺杂结构，这有助于其在光电器件中的应用。
