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 and then crystallized by Ar ion laser annealing technique. When the Ge well-layer thickness was reduced below about 4nm, the crystallized samples showed a room temperature photoluminescence peak at visible wavelength region. Obvious shift of the photoluminescence peak energy by changing the well-layer thickness was observed. A preliminary discussion about the origin of such visible photoluminescence phenomenon was proposed.