识别和删除金属氧化物半导体Schottky Si光电极的界面状态,以获得最高的填充因子
Jiangping Ma1,2, Haibo Chi2,3, Aoqi Wang2,3
1Key Laboratory of Advanced Catalysis, Gansu Province; State Key Laboratory of Applied Organic Chemistry, College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou, Gansu 730000, China.
Journal of the American Chemical Society
|September 14, 2022
概括
减少电极接口的缺陷是有效的太阳能转换的关键. 一层超薄的氧化 (AlO) 与黄金 (Au) 结合,有效地减少缺陷,提高光电化学水氧化效率.
科学领域:
- 材料科学
- 电化学
- 太阳能发电
背景情况:
- 由于不利的缺陷,高效的Schottky型 (Si) 光电极在异质接口上受到电荷提取损失的阻碍.
- 了解界面特征与光转换效率之间的相关性对于推进太阳能技术至关重要.
研究的目的:
- 使用n-Si/氧化物 (MOx) /Ni作为模型系统,研究接口特征对电荷传输和光电/光电化学 (PEC) 性能的影响.
- 识别和减轻Si heterointerface上的缺陷,以提高光转换效率.
主要方法:
- 具有不同界面层的n-Si/氧化物/Ni异构的制造和表征,包括超薄的AlOx和Au.
- 使用光电和PEC测量分析界面电子状态,电荷载体动态和缺陷诱导的重组.
- 在PEC水氧化中对最终光电极 (n-Si/SiO2/AlOx/Au/Ni/NiFeOx) 的性能进行评估.
主要成果:
- 一个超薄的AlOx层减少了接口钉,但引入了深层的捐赠器样缺陷 (0.59 eV低于导电带),导致~10%的电荷重组.
- 将AlOx与薄的Au层 (AlOx/Au双间层) 结合起来,有效地消除了这些缺陷,并优化了电场的电荷提取.
- 优化的n-Si/SiO2/AlOx/Au/Ni/NiFeOx光电极实现了0.75的记录填充系数和3.71%的偏移光子对电流效率 (ABPE).
结论:
- 界面工程对于最小化缺陷和最大化基于Si的光电极的电荷提取至关重要.
- 双层AlOx/Au策略有效地抑制有害的接口状态,显著提高光转换效率.
- 这项工作提供了对接口电子状态的基本见解,以及它们在增强太阳能转化为化学能量的关键作用.
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