The Surface Treatments On Porous Silicon And Their Influence On Photoluminescence

Porous silicon shows strong visible luminescence and is regarded as a potential material for illumination and photoelectric integration; however, as stored in air, photoluminescence (PL) intensity of porous silicon (PS) decreases gradually, and the PL instability has become an obstruction to the practical application of PS. A series of techniques were adopted in this thesis to improve the PL properties of PS, and the PL intensity is significantly enhanced.This thesis investigates the effect of different activity low energy ion irradiation on PL of PS. In the case of argon ion irradiation, PL is firstly quenched after argon ion irradiation, then recovered as the post-irradiated PS stored in air and reaches a maximum which is still lower than that of as-etched PS; the PL quenching is due to the defects created by ion irradiation, whereas the PL recovery originates from the oxidation of Si-H back bonds and the formation of radiative recombination centers. In the case of nitrogen ion irradiation, the Si-N bonds formed on the surface of PS and help to obtain high PL intensity. As for oxygen ion irradiation, the Si-H bonds are oxidized by oxygen ions, and a layer of nonstoishiometric SiOx (1