新型SiAsP二维Janus材料电子结构和光吸收性质的第一性原理研究

A first-principles study on the electronic structure and light absorptionproperties of novel SiAsP two-dimensional Janus materials

基于密度泛函理论的第一性原理计算,通过对最新报道出的二维材料单层SiP_(2)进行原子替换,预测出单层SiAs_(2),α-SiAsP,β-SiAsP 3种新型二维材料,并对3种材料的晶体结构、稳定性、电子能带结构和光学性质进行分析验证。通过静电势计算验证出3种材料在与平面垂直的方向具有非对称性,是Janus材料;声子谱计算结构表明3种材料具有良好的结构稳定性;电子结构计算结果表明上述材料为间接带隙半导体,带隙大小分别为2.21,2.43,1.76 eV;吸收光谱计算结果表明3种材料可以有效地吸收可见光和紫外光,其中β-SiAsP甚至可以吸收近红外光。因此,预测出单层SiAs2,α-SiAsP和β-SiAsP二维Janus材料在光学和电子领域具有一定的应用前景。

Based on the new emerging two-dimensional(2D)material of SiP_(2),this work proposes three novel 2D materials:monolayer SiAs_(2),α-SiAsP andβ-SiAsP by the first-principles calculation of density functional theory.Electrostatic potential calculation shows that the three materials are asymmetric in the directions perpendicular to the plane,and are Janus materials.The above materials possess high structural stability and are indirect semiconductors with band gap of 2.21,2.43 and 1.76 eV,respectively.More interestingly,they can effectively absorb visible as well as ultraviolet light.Moreover,β-SiAsP is even capable of absorbing near-infrared light.Therefore,2D monolayer SiAs_(2),α-SiAsP andβ-SiAsP Janus materials have certain application prospects in the field of optics and electronics.