Theoretical Analysis of Explosively Propagating Molten Layers in Pulsed-Laser-Irradiated<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>a</mml:mi><mml:mo>−</mml:mo><mml:mi mathvariant="normal">Si</mml:mi></mml:math>

Abstract

Nanosecond-pulsed-laser melting of amorphous ($a$) Si on crystalline ($c$) Si substrates produces a highly undercooled liquid ($l$) that solidifies into a complex morphology. Recently developed techniques for including undercooling, interface kinetics, and nucleation in heat-flow calculations are used to analyze the experimental results. It is shown how explosive crystallization, involving the difference in the $a$- and $c$-phase latent heats, can produce a nearly self-sustaining crystallization front mediated by a thin $l$ layer.