原生缺陷依赖的超快速载体动力学在p型可合的宽带间隔NiO中
Zhan Hua Li1,2, Jia Xing He3,4, Jia Yu Li3
1School of Electronic Science and Engineering, Nanjing University, Nanjing, Jiangsu 210023, China.
The journal of physical chemistry letters
|December 23, 2024
概括
在具有不同原生缺陷的氧化 (NiO) 膜中研究载体动力学揭示了不同的光物理行为. 了解这些动态对于推进NiO光电子和光催化剂至关重要.
科学领域:
- 材料科学 材料科学 材料科学
- 固态物理 固态物理
- 摄影化学的使用.
背景情况:
- 氧化 (NiO) 是一种p型金属氧化物,在光电子和光催化中具有重要的应用.
- 了解NiO中的载体动态对于设备优化至关重要,但仍未得到充分探索.
- 原生缺陷显著影响了NiO的电子特性.
研究的目的:
- 用 femtosecond 短暂吸收光谱学研究具有不同原生缺陷的 NiO 薄膜中的载体动态.
- 阐明氧空缺 (VO) 和空缺 (VNi) 在载体行为中的作用.
- 为优化基于 NiO 的设备性能提供见解.
主要方法:
- 五秒短暂吸收光谱法被用来探测载体动态.
- 研究了两种类型的NiO薄膜:含有氧空位的无化NiO和含有氧的NiO (NiO1+δ) 含有空位.
- 光谱分析的重点是光诱导的吸收和光漂白信号.
主要成果:
- 观察到明显的光谱特征:广泛的光诱导吸收在未化NiO和光漂白在富含O的NiO.
- 小电子极子 (SEP) 迅速形成 (<200 fs).
- 载体捕获发生在局部状态 (1-8 ps为未使用的NiO,5-7 ps为NiO1+δ),随后通过原生缺陷 (200 ps为VO,~2 ns为VNi) 缓慢的捕获/再组合.
结论:
- 原生缺陷 (VO和VNi) 在NiO薄膜中显著改变载体动态.
- 这项研究揭示了光生成载体捕获和重组的独特途径.
- 这些发现为设计基于NiO的高性能光电子和光催化器件提供了基本的见解.
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