Bertoluzzi Luca, Bisquert Juan
Department of Materials Science and Engineering, Stanford University , Stanford, California 94305, United States.
Institute of Advanced Materials (INAM), Universitat Jaume I , 12006 Castelló, Spain.
J Phys Chem Lett. 2017 Jan 5;8(1):172-180. doi: 10.1021/acs.jpclett.6b02714. Epub 2016 Dec 16.
The optimization of solar energy conversion devices relies on their accurate and nondestructive characterization. The small voltage perturbation techniques of impedance spectroscopy (IS) have proven to be very powerful to identify the main charge storage modes and charge transfer processes that control device operation. Here we establish the general connection between IS and light modulated techniques such as intensity modulated photocurrent (IMPS) and photovoltage spectroscopies (IMVS) for a general system that converts light to energy. We subsequently show how these techniques are related to the steady-state photocurrent and photovoltage and the external quantum efficiency. Finally, we express the IMPS and IMVS transfer functions in terms of the capacitive and resistive features of a general equivalent circuit of IS for the case of a photoanode used for solar fuel production. We critically discuss how much knowledge can be extracted from the combined use of those three techniques.
太阳能转换装置的优化依赖于其准确且无损的表征。阻抗谱（IS）的小电压扰动技术已被证明在识别控制器件运行的主要电荷存储模式和电荷转移过程方面非常强大。在这里，我们为将光转换为能量的一般系统建立了IS与光调制技术（如强度调制光电流（IMPS）和光电压谱（IMVS））之间的一般联系。随后，我们展示了这些技术如何与稳态光电流、光电压以及外部量子效率相关。最后，对于用于太阳能燃料生产的光阳极情况，我们根据IS的一般等效电路的电容和电阻特性来表达IMPS和IMVS传递函数。我们批判性地讨论了从这三种技术的联合使用中可以提取多少知识。
