Abstract: There is described a method for crystallizing films selected from the group comprising the amorphous elementary semi-conducting films and the polymetallic films comprised of two elements belonging respectively to Groups III and V, or Groups II and VI of the Periodic Table, which comprises irradiating the film surface with a laser beam guided by an assembly from optic fibers which are arranged in parallel relationship with one another, each fiber having a diameter which is not larger than 50.mu., said irradiating causing crystallizing into crystallites which are regularly distributed and closely confined.

Abstract: There is described a method for preparing polycrystalline semi-conducting films comprised of two elements respectively from Groups III and V, or Groups II and VI of the Periodic Table, by irradiating with a laser beam a film which is comprised of at least two layers from elements selected with a stoichiometric ratio, said film being deposited over a non-crystalline substrate and being coated with a protective layer, which method is comprised of irradiating said film with a structured laser beam to cause crystallizing into crystallites which are regularly aligned and with a size at least equal to the thickness of the resulting film.