Laser-induced crystallization in amorphous films of (C = S, Se, Te), potential optical storage media

The amorphous-to-crystalline phase change induced by a continuous-wave laser was investigated systematically in the case of as-grown amorphous films of , and and results were compared. The photo-thermal process is found to be responsible for the phase change in all three compounds. The minimum threshold laser power required to induce optical contrast at an irradiated site was found to depend on the film thickness; however, the required power density was found to be of the order of for all three films. All three films exhibited good potential for use as the WORM kind of storage devices, films having the minimum threshold power. and films in the non-stoichiometric phase exhibited potential for reversible storage.