Use of nanocrystal thin films as active layers in optoelectronic devices requires tailoring of their electronic band structure. Here, we demonstrate energy-resolved electrochemical impedance spectroscopy (ER-EIS) as a method to quantify the electronic structure in nanocrystal thin films. This technique is particularly well-suited for nanocrystal-based thin films as it allows for in situ assessment of electronic structure during solution-based deposition of the thin film. Using well-studied lead sulfide nanocrystals as an example, we show that ER-EIS can be used to probe the energy position and number density of defect or dopant states as well as the modification of energy levels in nanocrystal solids that results through the exchange of surface ligands. This work highlights that ER-EIS is a sensitive and fast method to measure the electronic structure of nanocrystal thin films and enables their optimization in optoelectronic devices.

中文翻译：

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使用能量分辨电化学阻抗谱法测量纳米晶体薄膜的电子结构

将纳米晶体薄膜用作光电器件中的有源层需要定制其电子能带结构。在这里，我们展示了能量分辨电化学阻抗谱（ER-EIS）作为量化纳米晶体薄膜中电子结构的方法。该技术特别适合于基于纳米晶体的薄膜，因为它允许在基于溶液的薄膜沉积过程中对电子结构进行原位评估。以经过充分研究的硫化铅纳米晶体为例，我们表明，ER-EIS可用于探测缺陷或掺杂态的能级和数量密度，以及通过交换纳米颗粒而导致的纳米晶体固体能级的改变。表面配体。