Ultrahigh porosity photoluminescent silicon aerocrystals with greater than 50% nanocrystal ensemble quantum yields

Three types of mesoporous silicon flakes were fabricated by anodization in methanoic hydrofluoric acid from the same substrates (heavily doped p-type). Even though current density, rinsing, drying method, and storage condition for all three wafers, resulting porous (PSi) structures had very different properties. They colors. Two them showed quite high luminescence quantum yields (QYs), confirmed long lifetimes. The highest QY exceeded 50% a peak photoluminescence wavelength ∼750 nm. To date, this is obtained PSi importantly with large mesopores, which typically not highly efficient (as opposed to small mesopores microporous silicon). Large (>15 nm diameter) facilitate impregnation various substances into luminescent material, such as metals plasmonics drugs theranostics. differing properties correlated electrolyte temperature during anodization, evolution batch (lowering active fluoride content buildup hexafluorosilicate) used anodize several whose effects are often overlooked when mass-producing PSi. Supercritical completion slow growth native oxide passivation dark leading final partially oxidized also important factors QYs obtained. was structure having most isolated Si nanocrystals an amorphous tissue.