Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA.
J Chem Phys. 2013 Jan 14;138(2):024704. doi: 10.1063/1.4773583.
The electronic structure of Cu(2)O and CuO thin films grown on Cu(110) was characterized by X-ray photoelectron spectroscopy (XPS) and X-ray absorption spectroscopy (XAS). The various oxidation states, Cu(0), Cu(+), and Cu(2+), were unambiguously identified and characterized from their XPS and XAS spectra. We show that a clean and stoichiometric surface of CuO requires special environmental conditions to prevent loss of oxygen and contamination by background water. First-principles density functional theory XAS simulations of the oxygen K edge provide understanding of the core to valence transitions in Cu(+) and Cu(2+). A novel method to reference x-ray absorption energies based on the energies of isolated atoms is presented.
采用 X 射线光电子能谱（XPS）和 X 射线吸收谱（XAS）对 Cu（110）上生长的 Cu（2）O 和 CuO 薄膜的电子结构进行了表征。从 XPS 和 XAS 谱中可以明确地识别和表征出各种氧化态，Cu（0）、Cu（+）和 Cu（2+）。我们表明，要获得清洁且化学计量的 CuO 表面，需要特殊的环境条件来防止氧的损失和背景水的污染。基于孤立原子能量的新型 X 射线吸收能量参考方法被提出。氧 K 边的第一性原理密度泛函理论 XAS 模拟提供了对 Cu（+）和 Cu（2+）中芯到价跃迁的理解。
