Photophysics of organically-capped silicon nanocrystals - A closer look into silicon nanocrystal luminescence using low temperature transient spectroscopy

► We present a systematic study on the photophysics of silicon nanocrystals. ► We study 3 local environments - alkyl-capped, surface oxidized, oxide-encapsulate. ► Even alkyl-capped ncSi are strongly affected by oxide surface species. ► Lifetimes significantly increase and bandgap widens drastically at low temperature. ► Turn-on of defect-free luminescence occurs at temperatures below 100-150 K.