Laser-doping of crystalline silicon substrates using doped silicon nanoparticles

Crystalline Si substrates are doped by laser annealing of solution processed Si. For this experiment, dispersions of highly B-doped Si nanoparticles are deposited onto intrinsic Si and laser processed using an 807.5 nm continuous wave laser. During laser processing the particles as well as a surface-near substrate layer are melted to subsequently crystallize in the same orientation as the substrate. The doping profile is investigated by secondary ion mass spectroscopy revealing a constant B concentration of 2 x 10(18) cm(-3) throughout the entire analyzed depth of 5 mu m. Four-point probe measurements demonstrate that the effective conductivity of the doped sample is increased by almost two orders of magnitude. The absolute doping depth is estimated to be in between 8 mu m and 100 mu m. Further, a pn-diode is created by laser doping an n-type c-Si substrate using the Si NPs. (C) 2013 Published by Elsevier B. V.