Quantitative operando visualization of the energy band depth profile in solar cells.
Quantitative operando visualization of the energy band depth profile in solar cells.
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太阳能电池能带深度剖面的定量操作可视化
DOI：
10.1038/ncomms8745
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发表时间：
2015-07-13
影响因子：
16.6
通讯作者：
Chen L
中科院分区：
文献类型：
--
作者：
Chen Q;Mao L;Li Y;Kong T;Wu N;Ma C;Bai S;Jin Y;Wu D;Lu W;Wang B;Chen L
太阳能电池器件中的能带排列至关重要，因为它在很大程度上控制着基本的光伏过程，例如电荷载流子的产生、分离、传输、重组和收集。尽管花费了大量的精力，跨多层的能带深度分布的测量仍然极具挑战性，特别是对于操作设备而言。在这里，我们使用扫描开尔文探针显微镜直接可视化操作有机光伏器件横截面的表面电势深度剖面。由于有限的尖端尺寸和悬臂梁串扰造成的卷积效应以前禁止对扫描开尔文探针显微镜测量的表面电势深度剖面进行定量解释。我们开发了一种偏置电压补偿方法来解决这个关键问题，并获得开路电压、内置电位和电极电位差的定量准确测量。
The energy band alignment in solar cell devices is critically important because it largely governs elementary photovoltaic processes, such as the generation, separation, transport, recombination and collection of charge carriers. Despite the expenditure of considerable effort, the measurement of energy band depth profiles across multiple layers has been extremely challenging, especially for operando devices. Here we present direct visualization of the surface potential depth profile over the cross-sections of operando organic photovoltaic devices using scanning Kelvin probe microscopy. The convolution effect due to finite tip size and cantilever beam crosstalk has previously prohibited quantitative interpretation of scanning Kelvin probe microscopy-measured surface potential depth profiles. We develop a bias voltage-compensation method to address this critical problem and obtain quantitatively accurate measurements of the open-circuit voltage, built-in potential and electrode potential difference.