Photoelectric properties of porous and single-crystal silicon heterocontacts

The polarization photosensitivity of a heterocontact of porous and single-crystal silicon is experimentally investigated. A maximum in the photosensitivity is observed at ∼1 mA/W at energies in the range 1.2–2.3 eV, when linearly polarized light is obliquely incident on the surface of the porous-silicon layer. The photopleochroism of these heterostructures depends on the angle of incidence θ, varies roughly as ∼θ2, and reaches the maximum value of ∼32% at θ⋍80°. Oscillations due to interference of natural and linearly polarized light in the porous-silicon layers are observed in the photocurrent and the photopleochroism of these structures. Heterostructures consisting of a layer of porous silicon on a silicon single crystal can find application as photoconverters of natural and linearly polarized light.