Generation of a polarization sensitive photocurrent in a CuSe/Se nanocomposite thin film

CuSe-based structures are widely used in various fields of photonics and optoelectronics. It has been shown for the first time that a photocurrent depending on the direction of the wave vector and polarization of the incident radiation can be excited in thin films consisting of amorphous Se and CuSe nanocrystallites. Films on glass substrates have been obtained by the successive thermal deposition of selenium and copper in vacuum at room temperature. The photocurrent has been excited by radiation of a femtosecond laser at a wavelength of 795 nm at room temperature. It has been found that the longitudinal photocurrent measured in the direction of the plane of incidence is maximal at $p$-polarization and vanishes at $s$-polarization. The transverse pho-tocurrent perpendicular to the plane of incidence is an odd function of the polarization angle and is absent at $p$- and $s$-polarizations. In both cases, the photocurrent is an odd function of the angle of incidence of light on the film surface. The results obtained are in qualitative agreement with the theory of generation of the surface photogalvanic effect.