Nanosecond polarization-sensitive IR photoresponse of CuSe/Se nanocomposite film

Using sequential vacuum thermal deposition of Se and Cu onto a glass substrate, we synthesized plasmonic CuSe/Se thin-film material and measured its absorption coefficient, complex refractive index, and complex dielectric permittivity from 240 to 2500 nm. Experimental results demonstrate that in the infrared range, the photoresponse of the film exhibits high sensitivity to both the polarization and the angle of incidence of the nanosecond excitation laser pulse. At oblique incidence, the laser-to-photocurrent conversion coefficient is a linear function of the excitation photon energy across a broad wavelength range of 1.5-3.5 μm (0.827-0.354 eV).