Experimental determination of the electrical band-gap energy of porous silicon and the band offsets at the porous silicon/crystalline silicon heterojunction

Abstract

Photovoltaic and photocurrent measurements have been carried out on a series of samples consisting of porous silicon on top of crystalline silicon. From the experimental data set, the electrical band-gap energy of porous silicon is deduced to be (1.80\ifmmode\pm\else\textpm\fi{}0.02) eV, and the conduction-band and valence-band offsets at the porous silicon/crystalline silicon heterojunction are determined to be (0.12\ifmmode\pm\else\textpm\fi{}0.01) eV and (0.57\ifmmode\pm\else\textpm\fi{}0.03) eV, respectively. The results are compared to previous determinations and discussed.