Fabrication of black silicon using picosecond laser irradiation assisted by Se dopant film

Black silicon with micro-nano structures were fabricated by irradiating silicon with 1064nm laser pulses of 8.7-ps duration, 4.5 μJ per single pulse, 100mm/s scanning speed in vacuum, and doping the black silicon by irradiating the silicon coated with Si-Se bilayer film. SEM images show that the surface micron-scale grooves covered with nano-scale particles pattern was produced on Si for both the sample with no film and with Se film, but the surface structure are smoother and more uniform in the presence of Se film. EDS graph demonstrated the presence of Selenium in the black silicon micro-nano structures. Furthermore, Raman spectra results indicate that the micro-nano structured black silicon is still crystal phase.