Nanosecond Diffuse Reflectance Spectroscopy for In-Situ Analysis of Electron Back-Recombination and Dye Regeneration in Fully Functional, Highly Efficient, Opaque Dye-Sensitized Solar Cell Devices
Nanosecond Diffuse Reflectance Spectroscopy for In-Situ Analysis of Electron Back-Recombination and Dye Regeneration in Fully Functional, Highly Efficient, Opaque Dye-Sensitized Solar Cell Devices
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DOI：
10.1021/acs.jpcc.3c05382
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发表时间：
2023-11-20
影响因子：
3.7
通讯作者：
Moser，Jacques-E.
中科院分区：
文献类型：
--
作者：
Ghadiri，Elham;Moser，Jacques-E.
提出了一种改进的纳秒漫反射（DR）光谱系统的光学设计。首次采用纳秒DR光谱技术对高效不透明染料敏化太阳能电池器件（DSC）中的电子逆反应和染料再生过程进行了原位分析。高效DSC装置基于不透明TiO 2双层膜，其包括400 nm光散射颗粒和20 nm光学透明颗粒。基于传输的激光技术不适合研究这些或其他设备通过使用不透明的形貌的TiO 2薄膜。然而，时间分辨的DR闪光光解使得能够在各种各样的不透明或高度光吸收和光散射材料中探索光物理过程。我们通过实验验证了基于DR的光谱学的三个重要组成部分：光学配置，样品条件和理论定量光学模型。漫射光的大光学角度使得能够以相对低的功率进行有效的光收集和测量。我们测试了稳态和时间分辨的浓度依赖性的Kubelka-Munk理论的定量分析的时间分辨的结果，并观察到的电子背反应的动力学的强烈影响的TiO 2薄膜的形态参数。在50 μs的寿命下，由400 nm TiO 2颗粒和20 nm TiO 2颗粒制成的器件光电阳极中的电子反向复合动力学比迄今报道的20 nm颗粒（1 ms）快2个数量级。与电子背复合相反，染料再生过程不受TiO 2膜形态的影响。
An improved optical design for nanosecond diffuse reflectance (DR) spectroscopy is presented. The in-situ analysis of the electron back-reaction and dye regeneration processes in efficient opaque dye-sensitized solar cell devices (DSCs) was scrutinized for the first time using nanosecond DR spectroscopy. The efficient DSC device is based on an opaque TiO2double-layer film comprising 400 nm light-scattering particles and 20 nm optically transparent particles. Transmission-based laser techniques are not suitable for studying these or other devices by using the opaque morphologies of TiO2films. However, time-resolved DR flash photolysis enables the exploration of photophysical processes in a broad variety of opaque or highly light-absorbing and light-scattering materials. We experimentally verified the three important components of DR-based spectroscopy: optical configuration, sample condition, and theoretical quantitative optical models. The large optical angle for diffusive light enables efficient light collection and measurement at a relatively low power. We tested the steady-state and time-resolved concentration dependence of the Kubelka–Munk theory for the quantitative analysis of time-resolved results and observed that the dynamics of electron back-reactions are strongly affected by the morphological parameters of the TiO2films. With a lifetime of 50 μs, the kinetics of electron back-recombination in the device’s photoanode, which is manufactured with 400 nm TiO2particles and 20 nm TiO2particles, are 2 orders of magnitude faster than what has been reported to date for 20 nm particles (1 ms). In contrast to electron back-recombination, the dye regeneration process is not influenced by the TiO2film morphology.