Formation of luminescent silicon by laser annealing of a-Si:H

We report the preparation of luminescent Si by laser annealing of amorphous hydrogenated silicon (a-Si:H) deposited on a silica substrate by glow-discharge deposition. For this process, we have used XeCl excimer laser pulses with an energy density in the range of 0.3–0.7 J/cm2. While no visible photoluminescence (PL) has been observed at room temperature from the unirradiated a-Si:H the PL comparable to the PL spectra of porous Si occurs in the irradiated part. The electron microscope studies reveal a microstructure which is a function of the pulse number and the pulse energy density.