The evolution investigation of photoluminescence from a-Si:H/SiO2 to nc-Si/SiO2 multilayers

Abstract

The evolution of photoluminescence (PL) at room temperature from a-Si:H/SiO2 to nc-Si/SiO2 multilayers was observed through step-by-step post-treatment. It is found that the Si dangling bonds caused by dehydrogenation result in an intensified PL peak at 700 nm. The competition between the role of Si dangling bonds and nc-Si is the origin of the weaker PL band, including two peaks at 700 and 775 nm. The enhancement of PL intensity of the peak at 775 nm is induced by the increase of the number of nc-Si and oxygen-related defects saturated by Si–O–Si within the Si/SiO2 interface. The relation between the evolution of PL and microstructure of the samples is discussed in detail.