First-principles energy band calculation for undoped and N-doped InTaO4 with layered wolframite-type structure
First-principles energy band calculation for undoped and N-doped InTaO4 with layered wolframite-type structure
复制标题
DOI：
10.1016/s0022-3697(03)00283-x
复制
发表时间：
2003-12
影响因子：
4
通讯作者：
S. Matsushima;K. Obata;Hiroyuki Nakamura;M. Arai;Kenkichiro Kobayashi
中科院分区：
文献类型：
--
作者：
S. Matsushima;K. Obata;Hiroyuki Nakamura;M. Arai;Kenkichiro Kobayashi
在密度泛函理论框架下，计算了结构优化后的未掺杂和N掺杂InTaO4的电子结构。计算得到的晶格常数与实验值吻合较好，误差在2%以内。价带极大值(VBM)位于ZD线的中点附近，导带极小值(CBM)位于DX线的中点附近。这意味着InTaO4是一种间接带隙材料，VBM和CBM之间的最小理论间隙约为3.7 eV。在−6.0-0 eV范围内，价带主要由O2p轨道组成，而在4d5s5p和Ta5d中，价带与O2p轨道略有杂化.另一方面，5.5 eV以下的导带主要由Ta5d轨道组成，In和O轨道的贡献很小。与未掺杂的InTaO4相比，N掺杂InTaO4的禁带宽度减小了0.3 eV，这是因为在价带顶部附近出现了来源于N2p轨道的新的带隙。这一结果表明，在金属氧化物中掺杂N原子是一种开发可见光敏感光催化剂的有效方法。
The electronic structures of undoped and N-doped InTaO4with optimized structures are calculated within the framework of the density functional theory. Calculated lattice constants are in excellent agreement with experimental values, within a difference of 2%. The valence band maximum (VBM) is located near the middle point on the ZD line and the conduction band minimum (CBM) near the middle point on the DX line. This means that InTaO4is an indirect-gap material and a minimum theoretical gap between VBM and CBM is ca. 3.7eV. The valence band in the range from −6.0 to 0eV mainly consists of O 2p orbitals, where In 4d5s5p and Ta 5d orbitals are slightly hybridized with O 2p orbitals. On the other hand, the conduction band below 5.5eV is mainly composed of the Ta 5d orbitals and the contributions of In and O orbitals are small. The band gap of N-doped InTaO4decreases by 0.3eV than that of undoped InTaO4, because new gap states originating from N 2p orbitals appear near the top of the valence band. This result indicates that doping of N atoms into metal oxides is a useful method to develop photocatalysts sensitive to visible light.