A Novel Ge Nanostructure Exhibiting Visible Photoluminescence

The a-Ge: H/a-SiN x : H multiquantum-well structures were prepared by a computer-controlled plasma enhanced chemical vapor deposition method and then crystallized by Ar + laser annealing technique. When the Ge well-layer thickness was reduced to 30 Å, the crystallized sample showed a room temperature photoluminescence with a peak at about 2.26 eV. Meanwhile some significant characteristics of such a novel Ge nanostructure were also revealed by x-ray diffraction. Possible mechanisms of this visible PL phenomenon have been discussed.