PHOTOELECTRIC PROPERTIES OF POROUS AND SINGLE-CRYSTAL SILICON HETEROCONTACTS

The polarization photosensitivity of a heterocontact of porous and sin gle-crystal silicon is experimentally investigated. A maximum in the p hotosensitivity is observed at similar to 1 mA/W at energies in the ra nge 1.2-2.3 eV, when linearly polarized light is obliquely incident on the surface of the porous-silicon layer. The photopleochroism of thes e heterostructures depends on the angle of incidence theta, varies rou ghly as similar to theta(2), and reaches the maximum value of similar to 32% at theta similar or equal to 80 degrees. Oscillations due to in terference of natural and linearly polarized light in the porous-silic on layers are observed in the photocurrent and the photopleochroism of these structures. Heterostructures consisting of a layer of porous si licon on a silicon single crystal can find application as photoconvert ers of natural and linearly polarized light. (C) 1997 American Institu te of Physics.