Enhancement of Electroluminescence from n-Type Porous Silicon and Its Photoelectrochemical Behavior

In a study of the electroluminescence (EL) of porous silicon on an n-type Si wafer using an S₂O₈^2- electrolyte solution, the addition of C₃H₅OH to the solution was found to enhance the intensity of EL from the porous silicon. The porous silicon structure was classified into two types which were prepared based on whether the anodizing current density for forming the porous n-Si was above or below the saturated photocurrent. A single layer of fine pores was formed galvanostatically with illumination at a current density below the saturated photocurrent density, and a double layer of fine and rough pores was formed under the same conditions but at a current density above the saturated photocurrent density. The electrochemical and enhanced electroluminescent properties of the two types of porous silicon were studied.