Size-dependent crystallization of Si nanoparticles

Crystallization temperature dependency on Si nanoparticles size was studied by using Raman scattering spectroscopy. Si nanoparticles synthesized by pulsed laser ablation were annealed at various temperatures while they were suspended in helium background gas, and then were classified by a differential mobility analyzer. After the size classification, Si nanoparticles showed a narrow size distribution which enabled investigation of the size-dependent crystallization. The temperature threshold for the transition from amorphous to crystalline (Tc) decreased as the particle size decreased: the Tc values of the 10, 8, 6, and 4nm particles were 1273, 1173, 1073 and 773K, respectively.