关键词: 多孔硅, 电致发光, 光谱红移, 量子限制效应

Abstract: The electroluminescence (EL) of ntype porous silicon (PS) in a persulphate solution under cathodic polarization was studied. A significant red shift in the luminescence spectra with the increase of polarization time, as well as a blue shift with the increase of cathodic polarization, have been found. FTIR, MicroRaman, AFM and photoelectrochemical techniques have been used to investigate the structure of PS before and after the electroluminescence emission. All these results show that the surface of PS has been oxidized by the persulphate during the EL emission, and accompanied by the stripping of small silicon nanocrystallite, which leades to the red shift of the electroluminescence spectrum. Both of the voltagetunable electroluminescence and the timedependent red shift of the EL spectra support that quantum confinement effect (QCE) plays an important role in the electroluminescence in liquid contact.