利用第一性原理赝势平面波方法计算了杂质(X=C,Al)掺杂新型二维材料磷烯的结构参数、能带结构、Mulliken布居分析、差分电荷密度以及光学性质。结果表明杂质掺杂后磷烯材料的结构发生了畸变,但是掺杂体系的结构是稳定的。C掺杂后,费米...利用第一性原理赝势平面波方法计算了杂质(X=C,Al)掺杂新型二维材料磷烯的结构参数、能带结构、Mulliken布居分析、差分电荷密度以及光学性质。结果表明杂质掺杂后磷烯材料的结构发生了畸变,但是掺杂体系的结构是稳定的。C掺杂后,费米能级进入价带中,带隙变窄,变为0.826 e V的直接带隙;Al掺杂后,体系变为间接带隙半导体,带隙略有展宽,带隙为0.965 eV。Mulliken布居分析和差分电荷密度的分析都表明掺杂后体系的电荷分布发生了转移,C原子附近出现了电荷积累,而Al原子附近出现了电荷消耗。在(100)极化方向上的光学性质计算表明:在红光及红外线的范围内,C掺杂后磷烯材料储存电磁能的能力有所减弱,而Al掺杂后储存电磁能的能力有所增强;C掺杂后折射率n0减小,Al掺杂后折射率n0增大;吸收系数和反射率峰值均降低;掺杂前后磷烯材料都可作为光储存材料。以上结果说明采用不同杂质掺杂可以调制磷烯材料的光电性质。展开更多
The β-FeSi2 thin film has been applied in the research field of the solar cell,and the thickness of β-FeSi2 absorption layer was chosen through the experiments.However,Up to now neither the optimal thickness of β-F...The β-FeSi2 thin film has been applied in the research field of the solar cell,and the thickness of β-FeSi2 absorption layer was chosen through the experiments.However,Up to now neither the optimal thickness of β-FeSi2 absorption layer nor the relationship between the thickness of β-FeSi2 absorption layer and the solar photo wavelength has been theoretically studied.In this paper,the relationship between the thickness of the absorption layer of β-FeSi2 thin film solar cell and the solar photo wavelength is calculated and analyzed by theory.The results show that the thickness of the absorption layer of β-FeSi2 is at least 200 nm when the optical absorption efficiency of the solar energy reaches 90%,and that the optimal thickness range is from 200 nm to 250 nm,and that the optimal wavelength of the photon absorbed by β-FeSi2 thin film solar cell is from 0.46 μm？0.6 μm.Furthermore,two formulas are put forward to indicate the relationship between the thickness of the absorption layer of β-FeSi2 thin film solar cell and the solar photo wavelength.The thickness of the absorption layer of β-FeSi2 thin film solar cell increases linearly with the solar photo wavelength within the optimal photo wavelength.The formulas provide a reliable theoretical basis of determining the thickness of the β-FeSi2 thin film in the solar cell.展开更多
文摘利用第一性原理赝势平面波方法计算了杂质(X=C,Al)掺杂新型二维材料磷烯的结构参数、能带结构、Mulliken布居分析、差分电荷密度以及光学性质。结果表明杂质掺杂后磷烯材料的结构发生了畸变,但是掺杂体系的结构是稳定的。C掺杂后,费米能级进入价带中,带隙变窄,变为0.826 e V的直接带隙;Al掺杂后,体系变为间接带隙半导体,带隙略有展宽,带隙为0.965 eV。Mulliken布居分析和差分电荷密度的分析都表明掺杂后体系的电荷分布发生了转移,C原子附近出现了电荷积累,而Al原子附近出现了电荷消耗。在(100)极化方向上的光学性质计算表明:在红光及红外线的范围内,C掺杂后磷烯材料储存电磁能的能力有所减弱,而Al掺杂后储存电磁能的能力有所增强;C掺杂后折射率n0减小,Al掺杂后折射率n0增大;吸收系数和反射率峰值均降低;掺杂前后磷烯材料都可作为光储存材料。以上结果说明采用不同杂质掺杂可以调制磷烯材料的光电性质。
基金supported by National Natural Science Foundation of China (Grant No. 60766002)the Key International Collaborative Project of Ministry of Science and Technology of China (Grant No.2008DFA52210)Project of Science and Technology Department of Guizhou Province,China (Grant No. 0831)
文摘The β-FeSi2 thin film has been applied in the research field of the solar cell,and the thickness of β-FeSi2 absorption layer was chosen through the experiments.However,Up to now neither the optimal thickness of β-FeSi2 absorption layer nor the relationship between the thickness of β-FeSi2 absorption layer and the solar photo wavelength has been theoretically studied.In this paper,the relationship between the thickness of the absorption layer of β-FeSi2 thin film solar cell and the solar photo wavelength is calculated and analyzed by theory.The results show that the thickness of the absorption layer of β-FeSi2 is at least 200 nm when the optical absorption efficiency of the solar energy reaches 90%,and that the optimal thickness range is from 200 nm to 250 nm,and that the optimal wavelength of the photon absorbed by β-FeSi2 thin film solar cell is from 0.46 μm？0.6 μm.Furthermore,two formulas are put forward to indicate the relationship between the thickness of the absorption layer of β-FeSi2 thin film solar cell and the solar photo wavelength.The thickness of the absorption layer of β-FeSi2 thin film solar cell increases linearly with the solar photo wavelength within the optimal photo wavelength.The formulas provide a reliable theoretical basis of determining the thickness of the β-FeSi2 thin film in the solar cell.
