Blue light emission in nc-Si/SiO2 multilayers fabricated using layer by layer plasma oxidation

Abstract We report a new fabrication method of a-Si:H/SiO2 multilayers by using well-controlled layer by layer plasma oxidation in plasma enhanced chemical vapor deposition (PECVD) system. The blueshift of the absorption edge and photoluminescence (PL) peak from as-deposited a-Si:H/SiO2 multilayers is observed when the a-Si:H sublayer thickness decreases from 3.8 to 1.5 nm. A strong room-temperature blue PL (∼425 nm) is clearly observed, for the first time, in crystallized a-Si:H/SiO2 multilayers in addition to PL at 800 nm. In combination with Raman, TEM and PL measurements, the origin of the blue light emission is briefly discussed.