The Surface Photogalvanic and Photon Drag Effects in Ag/Pd Metal-Semiconductor Nanocomposite.

Aleksandr S Saushin,Gennady M Mikheev,Yuri P Svirko,Viatcheslav V Vanyukov

doi:10.3390/nano11112827

Aleksandr S Saushin, Gennady M Mikheev + Show 2 more

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https://doi.org/10.3390/nano11112827

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Abstract

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 s-polarized excitation beam produces a monopolar photoresponse, while at p-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.

Highlights

Irradiation of the metallic and semiconductor materials with laser pulses can lead to the generation of a photocurrent, which depends on the polarization and incidence angle of the laser beam
One can see that at p-polarized excitation, photocurrent pulses are bipolar and consist of short-front and long-tail parts, while for the s-polarized excitation beam, the photoresponse pulse is monopolar
We have recently demonstrated [14] that the bipolar photocurrent pulses are a consequence of the interplay of counter-flowing surface photogalvanic effect (SPGE) and photon drag effect (PDE) photocurrents generated in the Ag/Pd film

Summary

Introduction

Irradiation of the metallic and semiconductor materials with laser pulses can lead to the generation of a photocurrent, which depends on the polarization and incidence angle of the laser beam. This phenomenon can be described in terms of the second-order susceptibility of the medium that can be revealed from the measured photocurrent. The transfer of photons momenta to the free carriers is referred to as the photon drag effect (PDE) [3,4], which leads to the photocurrent in the conductive medium Both SPGE and PDE are second-order nonlinear optical effects that can be observed in non-centrosymmetric and centrosymmetric media [5]

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