BaSi as a promising low-cost, earth-abundant material with large optical activity for thin-film solar cells: A hybrid density functional study
BaSi as a promising low-cost, earth-abundant material with large optical activity for thin-film solar cells: A hybrid density functional study
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DOI：
10.7567/apex.7.071203
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发表时间：
2014-07-01
影响因子：
2.3
通讯作者：
Imai, Motoharu
中科院分区：
文献类型：
--
作者：
Kumar, Mukesh;Umezawa, Naoto;Imai, Motoharu
采用混合密度泛函理论，我们揭示了 BaSi2 大吸收系数的起源，在 h omega - E-g= 0.5 eV 时，BaSi2 大约比其他传统吸收体（例如 Si、GaAs、CdTe、CuInSe2 和 Cu2ZnSnS4）大 2 到 80 倍。这是根据 BaSi2 的电子能带结构来解释的，其中由于局域 Ba-d 态，最低导带 (CB) 具有较小的色散，从而产生平带。因此，这些平带有助于低能区域的广泛光学吸收，并导致 BaSi2 具有高光学活性。 (C) 2014 日本应用物理学会
Employing a hybrid density functional theory, we reveal the origin of the large absorption coefficient in BaSi2, which is roughly two to eighty times larger at h omega - E-g= 0.5 eV than other conventional absorbers such as Si, GaAs, CdTe, CuInSe2, and Cu2ZnSnS4. This is explained on the basis of the electronic band structure of BaSi2, whereby the lowest conduction band (CB) has a small dispersion, owing to the localized Ba-d states, resulting in flat bands. Consequently, these flat bands contribute to a wide range of optical absorption in the low-energy region and lead to high optical activity in BaSi2. (C) 2014 The Japan Society of Applied Physics