Self-sustained cyclic tin induced crystallization of amorphous silicon

Experimental evidences for a recently proposed mechanism of tin-induced crystallization of amorphous silicon are presented. The mechanism discusses a crystalline phase growth through cyclic processes of formation and decay of a super-saturated solution of silicon in molten tin at the interface with the amorphous silicon. The suggested mechanism is validated using a nonlinear dynamical model that takes into account the mass diffusion of the components of the system, heat transfer caused by latent (crystallization) heat release and amorphous silicon dissolution events, and concentration nonuniformities created by silicon crystallization. The analysis of a stationary-state solution of the model confirms the existence of periodic solutions for the partial volume of the crystalline phase and other system’s variables. Possible applications of the proposed mechanism in manufacturing of cost-effective nanocrystalline silicon films for the third-generation solar cell technology are discussed.