Light-emitting nanostructures formed by intense, ultrafast electronic excitation in silicon (100)

The intense, ultrafast electronic excitation of clean silicon (100)-(2x1) surfaces leads to the formation of silicon nanostructures embedded in silicon, which photoluminescence at similar to 560 nm wavelength (similar to2 eV band gap). The silicon surfaces were irradiated with slow, highly charged ions (e.g., Xe44+ and Au53+) to produce the electronic excitation. The observation of excitonic features in the luminescence is particularly unusual for silicon nanostructures. The temperature dependence and the measurement of the triplet-singlet splitting of the emission strongly support the excitonic assignment. (C) 2001 American Institute of Physics.