VOLTAGE-CONTROLLED SPECTRAL SHIFT OF POROUS SILICON ELECTROLUMINESCENCE

In this paper, it is reported that the electroluminescence (EL) of por ous silicon shows a reversible spectral shift as large as 270 nm for a n external bias variation of 0.6 V. This electroluminescence is obtain ed upon cathodic polarization of lightly doped n-type porous silicon i n contact with aqueous persulphate solutions. The study of the EL beha vior as a function of the external voltage and the persulphate ion con centration proves that while the amplitude of the EL is proportional t o the intensity of the exchanged current, the spectral position is onl y determined by the applied voltage.