Exciton absorption in β-FeSi2 epitaxial films
Exciton absorption in β-FeSi2 epitaxial films
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β-FeSi2 外延薄膜中的激子吸收
DOI：
10.1063/1.123426
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发表时间：
1999
影响因子：
4
通讯作者：
S. Gramlich
中科院分区：
文献类型：
--
作者：
M. Rebien;W. Henrion;U. Müller;S. Gramlich
给出了半导体二硅化铁中激子跃迁的实验证据。用室温下的透射和反射光谱以及室温椭圆偏振光谱研究了β-FeSi_2/Si（100）外延膜。在低温谱中发现了两个尖锐的峰，分别对应于激子的基态和第一激发态。假设自由的Wannier-Mott激子，得到的结合能值为16 meV。在这种假设下，电离能的值为0.93 eV。这与在10 K下测定的直接能隙值一致。与室温相比，能隙蓝移了40 meV。
Experimental evidence is given for excitonic transitions in semiconducting iron disilicide. Epitaxial films of β-FeSi2 on Si(100) were studied by optical transmission and reflection measurements at 10 K and at room temperature as well as room temperature spectral ellipsometry. Two sharp peaks were found in the low temperature spectra, which can be ascribed to the ground state and the first excited state of excitons. Assuming free Wannier–Mott excitons, a value of 16 meV is obtained for the binding energy. A value of 0.93 eV for the ionization energy results with this assumption. This coincides with the value of the direct energy gap determined at 10 K. Compared to room temperature the energy gap is blue shifted by 40 meV.