Group-IIIA versus IIIB delafossites: Electronic structure study
Group-IIIA versus IIIB delafossites: Electronic structure study
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DOI：
10.1103/physrevb.80.035205
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发表时间：
2009
影响因子：
3.7
通讯作者：
M. Huda;Yanfa Yan;A. Walsh;S. Wei;M. Al‐Jassim
中科院分区：
文献类型：
--
作者：
M. Huda;Yanfa Yan;A. Walsh;S. Wei;M. Al‐Jassim
第一性原理密度泛函理论计算揭示了IIIA族和IIIB族铜铁矿CuMO{sub 2}之间显著不同的行为。IIIA族铜铁矿具有间接带隙，直接带隙和间接带隙之间存在较大差异。然而，对于IIIB族铜铁矿，这种差异很小：对于库斯科{sub 2}仅为0.22 eV，并且对于CuYO{sub 2}和CuLaO{sub 2}，这种差异进一步减小。此外，而第IIIA族喜欢菱面体堆叠，第IIIB族稳定在六方结构。我们进一步发现库斯科{sub 2}在所有铜铁矿氧化物中具有最高的计算基本带隙。此外，CuLaO{sub 2}具有直接带隙.这些差异是由IIIA族和IIIB族元素之间不同的原子构型解释的。我们对这些铜铁矿的理解为正确选择铜铁矿在光电器件中的合适应用提供了一般指导。
First-principles density-functional theory calculations reveal significantly different behavior between group-IIIA and IIIB delafossites CuMO{sub 2}. The group-IIIA delafossites have indirect band gaps with large differences between the direct and indirect band gaps. However, this difference is small for the group-IIIB delafossites: only 0.22 eV for CuScO{sub 2} and it diminishes further for CuYO{sub 2} and CuLaO{sub 2}. Also, whereas group IIIA prefers rhombohedral stacking, group IIIB stabilizes in hexagonal structures. We further find that CuScO{sub 2} has the highest calculated fundamental band gap among all the delafossite oxides. In addition, CuLaO{sub 2} is found to have a direct band gap. These differences are explained by the different atomic configurations between the group-IIIA and IIIB elements. Our understanding of these delafossites provides general guidance for proper selection of delafossites for suitable applications in optoelectronic devices.