Abstract When a semiconductor is under photoexcitation, the voltage response to a temperature gradient is the photo-Seebeck effect. Here we study this effect, focusing on the contribution from transport of photo-excited carriers. We demonstrate that by combining photo-Seebeck with photoconductivity measurements, one can determine the ratio between electron and hole mobilities, and hence both of them when one is known. This is found for the case of defect-free samples, where no detail on the absorbance, carrier lifetime or recombination is necessary. Our method reported here does not require chemical doping, which could introduce defects and is often not feasible. It applies to both thin film and bulk samples. Experiment wise, photo-Seebeck effect is relatively easy to implement, or added to existing systems. In a broader context, for semiconductors with significant influence from defects, our result suggests that the photo-Seebeck behavior can still be understood. In this case another photo-transport property is necessary, in order to identify the mobilities of carriers and information regarding the defects. This framework integrates the information from photoexcitation and thermal gradients to provide a general method to determine fundamental electronic properties of materials.

中文翻译：

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使用 Photo-Seebeck 效应评估单个散装样品的电子和空穴迁移率的比率

摘要 当半导体处于光激发状态时，电压对温度梯度的响应是光-塞贝克效应。在这里，我们研究了这种效应，重点关注光激发载流子传输的贡献。我们证明，通过将 photo-Seebeck 与光电导率测量相结合，可以确定电子和空穴迁移率之间的比率，因此当已知两者时，可以确定两者之间的比率。这适用于无缺陷样品的情况，其中不需要关于吸光度、载流子寿命或重组的详细信息。我们这里报告的方法不需要化学掺杂，这可能会引入缺陷并且通常不可行。它适用于薄膜和大块样品。在实验方面，photo-Seebeck 效应相对容易实现，或添加到现有系统中。在更广泛的背景下，对于受缺陷影响显着的半导体，我们的结果表明仍然可以理解 photo-Seebeck 行为。在这种情况下，另一个光传输特性是必要的，以便识别载流子的移动性和有关缺陷的信息。该框架整合了来自光激发和热梯度的信息，以提供一种确定材料基本电子特性的通用方法。