Photocurrents caused by the light scattering
Date/Time: 11:00 28-Jun-2022
Abstract:
Irradiation of media by light results in generation of dc electric currents. Two origins of the photocurrent are well established: (i) photon drag effect resulting from the photon momentum transfer to electrons at the light absorption and (ii) photogalvanic effects caused by the asymmetry of the absorption, recombination, and scattering processes; the latter effects are allowed in noncentrosymmetric systems only [1]. It is generally accepted that if the light absorption is absent then the dc current cannot be generated and only transient currents take place [2]. Here we show that the dc current can be generated even if the light propagates in the transparency region of the crystal, but real electronic transitions take place due to the light scattering (similar effect have been mentionned in a recent preprint without detailed justifications [3]). We present the microscopic theory of the effect for the gyrotropic semiconductors and semiconductor nanosystems in the case of the incident and scattered photon energies below the band gap energy of the system.
This work has been supported by the RSF project #22-12-00211.
[1] B. I. Sturman and V. M. Fridkin. The photovoltaic and photorefractive effects in non-centrosymmetric materials. Gordon and Breach, New York, 1992.
[2] V. I. Belinicher, E. L. Ivchenko, and G. E. Pikus, Transient photocurrent in gyrotropic crystals, Sov. Phys. - Semicond. 20, 558 (1986)
[3] Y. Onishi, H. Watanabe, T. Morimoto, N. Nagaosa, Photovoltaic effect in noncentrosymmetric material without optical absorption, arXiv:2204.12727 (2022).
Video
Authors
Glazov Mikhail
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