MECHANISM OF ELECTROLUMINESCENCE OF POROUS SILICON IN ELECTROLYTES

A generalized model for the appearance of visible- and infrared-range electroluminescence of porous silicon in contact with an oxidizing ele ctrolyte is proposed. According to the model, visible-range electrolum inescence arises as a result of bipolar injection of electrons and hol es from the electrolyte into electrically insulated quantum-well silic on microcrystallites, while infrared-range electroluminescence is due to monopolar injection of holes from the electrolyte into macrocrystal s. A mechanism of electron injection from the electrolyte is proposed. It is concluded that the character of the electroluminescence should not depend on the magnitude and even the type of conductivity of the s ilicon substrate. (C) 1997 American Institute of Physics.