VISIBLE-LIGHT EMISSION FROM CRYSTALLIZED HYDROGENATED AMORPHOUS-GERMANIUM SILICON-NITRIDE MULTI-QUANTUM-WELL STRUCTURES

The a-Ge:H/a-SiN(X):H multiquantum-well structures were prepared by a computer-controlled plasma enhanced chemical vapor deposition method a nd then crystallized by Ar ion laser annealing technique. When the Ge well-layer thickness was reduced below about 4nm, the crystallized sam ples showed a room temperature photoluminescence peak at visible wavel ength region. Obvious shift of the photoluminescence peak energy by ch anging the well-layer thickness was observed. A preliminary discussion about the origin of such visible photoluminescence phenomenon was pro posed.