Electrical and photoelectrical properties of iodine modified porous silicon on silicon substrates

Abstract

Current-voltage characteristics, spectral dependences of photovoltage and short-circuit current of the structures based on porous silicon at adsorption of iodine molecules are presented. It is revealed widening the spectral range of photosensitivity in the samples in short-wavelength range as compared with that of single crystal silicon. Kinetics of the photovoltage response inherent to the porous silicon-silicon structures has been investigated. The results are explained in the frame of qualitative model that involves formation of p-n-transitions in these structures as a result of inversion of the conductivity type in porous silicon nanocrystals under the influence of adsorption of molecular iodine.

Modification of the Electrical Properties of Porous Silicon by Adsorption of Ammonia Molecules

“…On the other side, controlled adsorptions of chemically active or polar molecules purposefully modify the electrical parameters of silicon nanostructures. It was observed transformation of hole-type conductivity of mesoporous silicon into electronic one (see the case of adsorption of NH 3 molecules that exhibit donor properties [5]), or electronic-to-hole conductivity inversion (the case of adsorption of I 2 or Br 2 molecules revealing acceptor properties [6][7][8]). As a result, it was observed the appearance of photosensitive electrical barriers at the border PS -silicon substrate [7,8].…”

“…It was observed transformation of hole-type conductivity of mesoporous silicon into electronic one (see the case of adsorption of NH 3 molecules that exhibit donor properties [5]), or electronic-to-hole conductivity inversion (the case of adsorption of I 2 or Br 2 molecules revealing acceptor properties [6][7][8]). As a result, it was observed the appearance of photosensitive electrical barriers at the border PS -silicon substrate [7,8]. Nonetheless, applications of adsorption-based techniques for controlling the conductivity type have still not received sufficient attention from researchers.…”