PACS. 78.55.Hx Other solid inorganic materials - 61.46.+w Clusters, nanoparticles, and nanocrystalline materials - 78.45.+h Stimulated emission
Springer Online Journal Archives 1860-2000
Abstract: Silicon nanocrystals were prepared by Si+-ion implantation and subsequent annealing of SiO2 films thermally grown on a c-Si wafer. Different implantation energies (20-150 keV) and doses - cm -2 ) were used in order to achieve flat implantation profiles (through the thickness of about 100 nm) with a peak concentration of Si atoms of 5, 7, 10 and 15 atomic%. The presence of Si nanocrystals was verified by transmission electron microscopy. The samples exhibit strong visible/IR photoluminescence (PL) with decay time of the order of tens of μs at room temperature. The changes of PL in the range 70-300 K can be well explained by the exciton singlet-triplet splitting model. We show that all PL characteristics (efficiency, dynamics, temperature dependence, excitation spectra) of our Si+-implanted SiO2 films bear close resemblance to those of a light-emitting porous Si and therefore we suppose similar PL origin in both materials.
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