Nonlinear 1/f noise characteristics in luminescent porous silicon

We present noise characteristics of luminescent porous silicon and show tha t they shed light on the transport mechanism in this system. The 1/f fluctu ations show non-Gaussian and nonlinear behavior, and they give a high Hooge factor, typical of disordered conductors. By carrying out the measurements under various bias conditions, we found a bias-dependent redistribution of the percolating current paths. The close resemblance between the present r esults and those found in granular metals suggests that a tunneling process controlled by the electrostatic energy determines the conduction paths bet ween the nanocrystallites in luminescent porous silicon. (C) 1999 American Institute of Physics. [S0003-6951(99)02410-9].