Evolution of visible photoluminescence of Si quantum dots embedded in silicon oxide matrix

High Si content SRO/SiO2 bilayer superlattices with boron and phosphorus doping for next generation Si quantum dot photovoltaics

“…The Si NC size assessment from HRTEM correlates well with the GIXRD Scherrer equation estimates. Most previous HRTEM studies on lower Si content SRO have shown or suggested that the shape of the Si NCs are near spherical [4], [7], [19]- [23], but this not the case in this experiment as the average size for all three samples obtained from GIXRD are all greater than the thickness of the SRO layers which were only 4 nm prior to annealing. This could either mean that the Si NCs are penetrating through the adjacent 1.8 nm SiO 2 layers as suggested by Di et al [24] or there could be an extensive nanocrystalline Si network within the SRO layers making the Si NCs non-spherical in shape.…”

Synthesis and Properties of Luminescent Silicon Nanocrystal/Silica Aerogel Hybrid Materials

“…[33][34][35] Surprisingly, despite their chemical compatibility with silica and associated aerogels, only a small number of reports aim to combine the properties of these two important classes of materials. [36][37][38] Early SiNC-SiO 2 aerogel composites were prepared by either sol-gel processing of a mixture containing nanoscale Si and 4 silicon alkoxide precursors 36,37 or pressing powders of porous silicon and silica aerogels. 38 The SiNC-SiO 2 aerogel hybrids prepared using sol-gel processing were limited to comparatively large SiNCs (d > 10 nm) 36 or ill-defined porous silicon grains.…”

“…[36][37][38] Early SiNC-SiO 2 aerogel composites were prepared by either sol-gel processing of a mixture containing nanoscale Si and 4 silicon alkoxide precursors 36,37 or pressing powders of porous silicon and silica aerogels. 38 The SiNC-SiO 2 aerogel hybrids prepared using sol-gel processing were limited to comparatively large SiNCs (d > 10 nm) 36 or ill-defined porous silicon grains. 37 Silicon nanoparticles of these dimensions do not exhibit tunable photoluminescence (PL) -quantum confinement only impacts the properties of much smaller (d < 5 nm) nano-silicon particles.…”

“…Silicon nanocrystals (SiNCs) are nontoxic quantum dots whose optical response may be tuned through variations of NC size and surface chemistry. − Because of their exquisitely tunable electronic, optical, and chemical properties, SiNCs have demonstrated prototype applications as active materials in sensors, , batteries, , bioimaging, , drug delivery, , optoelectronic structures, , and photovoltaics. − Surprisingly, despite their chemical compatibility with silica and associated aerogels, only a small number of reports aim to combine the properties of these two important classes of materials. − Early SiNC-SiO 2 aerogel composites were prepared by either sol–gel processing of a mixture containing nanoscale Si and silicon alkoxide precursors , or pressing powders of porous silicon and silica aerogels . The SiNC-SiO 2 aerogel hybrids prepared using sol–gel processing were limited to comparatively large SiNCs ( d > 10 nm) or ill-defined porous silicon grains .…”