Visible photoluminescence from a nanocrystalline porous silicon structure fabricated by a plasma hydrogenation and annealing method

Abstract

Thin film nanocrystalline porous silicon layers have been fabricated from amorphous silicon films using dc plasma hydrogenation and subsequent annealing at temperatures about 450°C on silicon substrates. Plasma power densities about 5.5W∕cm2 were found to be suitable for etching of the silicon film and the creation of nanoporous layers. The nanoporous structures show visible luminescence at room temperature as confirmed by photoluminescence spectroscopy. The effects of plasma power and annealing temperature on the grain size and luminescence properties of these layers have been investigated by scanning electron microscopy, transmission electron microscopy, photoluminescence, and cathodoluminescence. It was observed that by lowering the temperature during the hydrogenation step, the diameter of the grains increased, whereas lowering the plasma power density caused the distribution of the porous surface structures to become less widely distributed and the formation of more packed structures. In addition, infrared spectroscopy has been used to investigate the origin of the light emitting behavior.

Investigation of luminescence from SiC nano-granule films on porous glass substrate

“…Furthermore, the optimal PL performance was obtained when SiC deposited time was 1 h and the glass substrate was etched for 20 min in the annealing sample (450 o C). [2][3][4][5][6][7] , the porous SiC [8,9] , the rare-earth doped SiC [10][11][12] and the SiO 2 -related materials [13] , have been extensively studied. Among them, silicon carbide has attracted special interests because it has potential applications on optoelectronics devices and high-temperature mechanical devices.…”