The effect of biaxial tensile deformation on the optoelectronic properties of Al-doped monolayers SnS₂ is explored using density functional theory. We found that the pure SnS₂ monolayer is an indirect bandgap semiconductor, and with Al doping it changes to a p-type semiconductor with a lowered bandgap value. After applying biaxial tensile deformation to the doped system, i.e., with the increase of tensile strain, bandgap value decreases. Analyzing the density of states, it is found that the conduction band in a doped system is primarily made of the Sn-5s orbital and the S-3p orbital, and the valence band is primarily made of Sn-5p orbital and S-3p orbital, with the majority of S-3p orbital. The conduction and valence bands change with the rise in tensile strain, and hence the gap in the density of states close to the Fermi energy level shrinks. It is also noticed that the absorption coefficient peaks and reflection peaks of the SnS₂ doped system subjected to biaxial tensile strain are blueshifted. The absorption coefficient and reflectance peaks of the doped system show a tendency to increase and then decrease with the increase of tensile strain.

利用密度泛函理论探讨了双轴拉伸变形对Al掺杂单层SnS _{2光电性能的影响。}我们发现纯SnS ₂单层是一种间接带隙半导体，掺杂Al后它会变成带隙值降低的p型半导体。对掺杂体系施加双轴拉伸变形后，即随着拉伸应变的增加，带隙值减小。分析态密度发现，掺杂体系中的导带主要由Sn-5s轨道和S-3p轨道组成，价带主要由Sn-5p轨道和S-3p轨道组成，大部分为 S-3p 轨道。导带和价带随着拉伸应变的增加而变化，因此接近费米能级的态密度间隙缩小。_{还注意到，SnS 2}掺杂系统经受双轴拉伸应变的吸收系数峰和反射峰发生蓝移。掺杂体系的吸收系数和反射率峰值随着拉伸应变的增加呈现先增大后减小的趋势。