Palacios P, Aguilera I, Sánchez K, Conesa J C, Wahnón P
Instituto de Energía Solar and Departamento Tecnologías Especiales ETSI Telecomunicación, UPM, Ciudad Universitaria, Madrid 28040, Spain.
Phys Rev Lett. 2008 Jul 25;101(4):046403. doi: 10.1103/PhysRevLett.101.046403. Epub 2008 Jul 23.
Results of density-functional calculations for indium thiospinel semiconductors substituted at octahedral sites with isolated transition metals (M=Ti,V) show an isolated partially filled narrow band containing three t2g-type states per M atom inside the usual semiconductor band gap. Thanks to this electronic structure feature, these materials will allow the absorption of photons with energy below the band gap, in addition to the normal light absorption of a semiconductor. To our knowledge, we demonstrate for the first time the formation of an isolated intermediate electronic band structure through M substitution at octahedral sites in a semiconductor, leading to an enhancement of the absorption coefficient in both infrared and visible ranges of the solar spectrum. This electronic structure feature could be applied for developing a new third-generation photovoltaic cell.
用孤立过渡金属（M = Ti、V）取代八面体位置的铟硫代尖晶石半导体的密度泛函计算结果表明，在通常的半导体带隙内，存在一个孤立的部分填充窄带，每个M原子包含三个t2g型态。由于这一电子结构特征，这些材料除了具有半导体的正常光吸收外，还能吸收能量低于带隙的光子。据我们所知，我们首次证明了通过在半导体的八面体位置进行M取代形成孤立的中间电子能带结构，从而导致太阳光谱红外和可见光范围内吸收系数的增强。这一电子结构特征可应用于开发新型第三代光伏电池。
