Relationship between the Photoluminescence Spectra and IR Spectroscopy of Mesoporous Silicon Samples during Long-Term Storage: The Effect of Immersion in an Aqueous LiBr Solutions

Studies are devoted to determining the effect of long-term storage (up to 200 days) of untreated and immersion-treated layers of mesoporous silicon in an aqueous lithium bromide solution obtained by anodizing with a current density of 10 mA/cm2 in electrolyte HF: CH3OH = 2: 1. It was found that an increase in the PL intensity and its saturation with a storage time of more than 100 days in all samples is observed. A detailed analysis of absorbance on bonds in m/por-Si showed that during storage, hydrogen bonds are destroyed, and the PL peak intensity is proportional to the increasing concentration of non-stoichiometric oxide, in which oxygen atoms forms radiative states. It was shown that in the treated samples, the PL intensity decreases with increasing immersion time, but the mechanism of photoluminescence through the quantum size confinement (QSC) effect in mesoporous silicon without and with immersion in an aqueous LiBr solution is not significant.