Enhanced photoluminescence property of porous silicon treated with bismuth (III)

This work focuses on the impact of Bismuth (Bi) solution treatment on the optical properties of p-type porous silicon prepared by electrochemical anodization. Bi-layers of variable thickness are incorporated in porous silicon via a dip coating technique. The changes in the structural and optical properties of Bi (III)/PS nanostructures are monitored by Atomic Force Microscopy, Fourier transform infrared measurements and photoluminescence spectroscopy. These analyses highlight a relevant impact of the deposition process, which modifies the intrinsic properties of the porous silicon by the incorporation of Bi (III) in its pores. It is found that ultra-thin films of bismuth oxide formed after a heat treatment in air at 400 °C and deposited on PS samples leads to its stability as well as to passivating its dangling bands. For thicknesses ranging from 6 to 20 nm, the photoluminescence property in the visible region of Bi/PS nanostructures has been improved. This may be of interest for various optoelectronic applications.