Saushin Aleksandr S, Mikheev Gennady M, Vanyukov Viatcheslav V, Svirko Yuri P
Institute of Photonics, University of Eastern Finland, FI-80101 Joensuu, Finland.
Institute of Mechanics, Udmurt Federal Research Center of the Russian Academy of Sciences, 426067 Izhevsk, Russia.
Nanomaterials (Basel). 2021 Oct 25;11(11):2827. doi: 10.3390/nano11112827.
We performed the investigation of the polarization-sensitive photocurrent generated in silver-palladium metal-semiconductor nanocomposite films under irradiation with nanosecond laser pulses at the wavelength of 2600 nm. It is shown that in both the transverse and the longitudinal configuration, the surface photogalvanic (SPGE) and photon drag effects (PDE) contribute to the observed photocurrent. However, the temporal profile of the transverse photocurrent pulse is monopolar at any polarization and angle of incidence, while the temporal profile of the longitudinal photocurrent pulse depends on the polarization of the excitation beam. Specifically, the irradiation of the film with the -polarized excitation beam produces a monopolar photoresponse, while at -polarized excitation, the photoresponse is bipolar, having a short front and long tail. Obtained experimental results are in agreement with the developed phenomenological theory, which describes transverse and longitudinal photocurrents due to SPGE and PDE in terms of relevant second-order nonlinear susceptibilities and allows us to obtain their dependences on the angle of incidence and polarization of the excitation laser beam. The pronounced dependence of the photocurrent on the angle of incidence and polarization of the excitation beam opens avenues toward the development of polarization- and position-sensitive detectors for industrial and space applications.
我们对银钯金属 - 半导体纳米复合薄膜在波长为2600 nm的纳秒激光脉冲照射下产生的偏振敏感光电流进行了研究。结果表明，在横向和纵向配置中，表面光生电流（SPGE）和光生载流子拖曳效应（PDE）都对观测到的光电流有贡献。然而，横向光电流脉冲的时间轮廓在任何偏振和入射角下都是单极的，而纵向光电流脉冲的时间轮廓取决于激发光束的偏振。具体而言，用偏振激发光束照射薄膜会产生单极光响应，而在偏振激发时，光响应是双极的，具有短前沿和长后沿。获得的实验结果与所发展的唯象理论一致，该理论根据相关的二阶非线性极化率描述了由于SPGE和PDE引起的横向和纵向光电流，并使我们能够获得它们对激发激光束入射角和偏振的依赖性。光电流对激发光束入射角和偏振的显著依赖性为开发用于工业和空间应用的偏振和位置敏感探测器开辟了道路。
