Photosensitive macroporous silicon based structures

Macroporous silicon prepared in n-type silicon have been used for a photosensitive device formation. Boron-doped spun-on layer was applied for p(+) emitter formation of the devices. The obtained structures Mere investigated by AFM and electron microscopy, photosensitivity and the photocurrent spectra were measured to evaluate the influence of porous layer and boron diffusion conditions. Unusually fast boron diffusion through the porous emitter was investigated, stipulating the p(+)-n junction to be positioned 2.5 mum deeper the poles bottom. This effect was explained by a presence of local electric fields, caused by tensions present at the border between PS layer and crystalline substrate and by possible deeper nanoporous structure, what was partially proofed by AFM.