Phase-field modeling of twin-related faceted dendrite growth of silicon

We investigated the growth of a twin-related silicon dendrite through a novel phase-field model. The correctness of the model for an equilibrium twined crystal was examined first before we modeled the faceted dendrite growth. The simulated morphologies of < 112 > and < 110 > faceted dendrites were consistent with experimental observations. The growth orientation of the simulated dendrite depended on the growth rates at the ridges and the re-entrant corners. We further extended the Twin-Plane-Reentrant-Edge (TPRE) mechanism and then proposed a new growth model for faceted dendrites based on our simulations. The undercooling and twin spacing could affect the growth rates at the ridges and the re-entrant corners, which were also explained by the proposed model. (C) 2016 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.