A Novel Ge Nanostructure Exhibiting Visible Photoluminescence

The a-Ge: H/a-SiN_x :H multiquantum-well structures were prepared by a computercontrolled plasma enhanced chemical vapor deposition method and then crystallized by Ar⁺ laser annealing technique. When the Ge well-layer thickness was reduced to 30Å, the crystallized sample showed a room temperature photoluminescence with a peak at about 2.26eV. 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.