Surface microstructures and photoluminescence characteristics of monocrystalline sillicon irradiated by 532 nm nanosecond laser

The evolution of silicon surface microstructures irradiated by Nd: YAG nanosecond laser pulses in the air under different laser fluences and scanning speeds was studied. The scanning electron microscope (SEM) images show that corrugated structure and porous structure are formed on the silicon surfaces after laser pulse irradiation. The photoluminescence (PL) spectra indicate a peak of luminescence at 710 nm. After corroding the SiOx on the silicon surfaces with hydrofluoric acid, the intensity of the luminescence peak greatly reduces, which proves that SiOx plays an important role in photoluminescence enhancement. The energy dispersive X-ray spectrum (EDS) shows that the amount of oxygen incorporated into the silicon surfaces depends on the laser fluence. Oxygen element in silicon surfaces has an important impact on enhancing PL emission.