Blue photoluminescence from nanocrystalline porous silicon structure fabricated by high-current pulsed electron beam irradiation

N-type Si (111) wafers have been processed by high-current pulsed electron beam (HCPEB) treatment with an increasing number of irradiation (1, 10 and 20 pulses). The results of this work show that a highly porous nanostructure was formed after irradiation. Moreover, the high-density Si nanocrystals (Si-ncs) about 3 nm were distributed on the surface of Si wafers and exhibited 3.02 eV Photoluminescence (PL) emission in blue band. The PL intensity increases with the increase in the Si-ncs' density in accordance with the quantum confinement model, which can be ascribed to the different pulse time of HCPEB treatment. The possible formation mechanisms of micropores and Si-ncs are discussed.