Low work function in the 122-family of iron-based superconductors
Low work function in the 122-family of iron-based superconductors
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DOI：
10.1103/physrevmaterials.4.034801
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发表时间：
2020-02
影响因子：
3.4
通讯作者：
H. Pfau;H. Pfau;H. Soifer;H. Soifer;J. Sobota;J. Sobota;A. Gauthier;A. Gauthier;C. Rotundu;J. C. Palmstrom;J. C. Palmstrom;I. Fisher;I. Fisher;G. Chen;H. Wen;Zhixuan Shen;Z. Shen;Zhixuan Shen;P. Kirchmann
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文献类型：
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作者：
H. Pfau;H. Pfau;H. Soifer;H. Soifer;J. Sobota;J. Sobota;A. Gauthier;A. Gauthier;C. Rotundu;J. C. Palmstrom;J. C. Palmstrom;I. Fisher;I. Fisher;G. Chen;H. Wen;Zhixuan Shen;Z. Shen;Zhixuan Shen;P. Kirchmann
我们用光电子能谱确定了铁砷化合物的功函数为：A={Ca，Ba，Cs}=2.7eV，BaFe$2=1.8eV，CsFe$2$=1.3 eV。这122个铁基超导体的功函数与元素金属$A的功函数相同，但要小得多。对这一现象最可能的解释是，解理表面只露出了$A$层的一半。BaFe$2$As$2$和CsFe$2$As$2$的低功函数和良好的光电发射截面使普通的白光LED也能进行光电发射。
We determine the work functions of the iron arsenic compounds $A$Fe$_2$As$_2$ ($A=\mathrm{Ca, Ba, Cs}$) using photoemission spectroscopy to be 2.7 eV for CaFe$_2$As$_2$, 1.8 eV for BaFe$_2$As$_2$, and 1.3 eV for CsFe$_2$As$_2$. The work functions of these 122 iron-based superconductors track those of the elementary metal $A$ but are substantially smaller. The most likely explanation of this observation is that the cleaving surface exposes only half an $A$-layer. The low work function and good photoemission cross section of BaFe$_2$As$_2$ and CsFe$_2$As$_2$ enable photoemission even from a common white LED light.