Yh. Ye et al., VISIBLE PHOTOLUMINESCENCE FROM GE-IMPLANTED SIO2-FILMS THERMALLY GROWN ON CRYSTALLINE SI(), Applied physics A: Materials science & processing, 67(2), 1998, pp. 213-217
Visible light emission from Ge+-implanted SiO2 films is studied as a f
unction of different fabricating conditions (implantation dose, anneal
ing temperature and time). The SiO2 films containing Ge nanocrystals e
xhibit two photoluminescence (PL) bands peaked at 600 nm and 780 nm. T
here are two excitation bands in the PL excitation (PLE) spectra. With
variation in Ge nanocrystal size, the PL and PLE peak energies show n
o appreciable shift. The PL and PLE spectral analyses suggest that dur
ing the PL process, electron-hole pairs are generated by the E(1) and
E(2) direct transitions inside Ge nanocrystals, which then radiatively
recombine via luminescent centers in the matrix or at the interface b
etween the nanocrystal/matrix.