Bulk silicon is unable to emit fluorescence because of its indirect band gap nature. However, it has been reported that nano-structured silicon can be fluorescent when properly excited. Silicon nanocrystals (SN) have gathered scientific attention not only because of their uncertain fluorescence origin, but also because of their advantages over fluorescent dyes. This thesis summarizes studies on the synthesis, characterization and bio applications of fluorescent SN. Size control of SN provided size dependent tuning of the fluorescence. Higher quantum yield and narrower size distribution of SN have been achieved. HrTEM, SANS, light scattering, photoluminescence and optical transmission spectroscopy on the size measurements of SN helped determine the average size accurately. Fuctionalization of surface prepares silicon nanocrystals as a platform for bio conjugating applications
