Optimizing heat dissipation in large-size cast Mono-Si furnace with a thermal switch hot-zone

Abstract

Cast monocrystalline silicon (mono-Si) is a promising photovoltaic material that offers significant advantages in cost-effectiveness and cell efficiency. However, challenges remain in its crystal quality, particularly due to uneven temperature distribution during the crystallization of large-size Si ingots. This study introduces an improved heat dissipation design with a thermal switch hot-zone featuring a movable plate, aimed at enhancing heat distribution at the bottom of the crucible. This modification reduces the lateral temperature gradient, stabilizes the solid-liquid interface, and improves crystal quality. Experimental results demonstrate that the thermal switch hot-zone design significantly shortens the growth cycle, accelerates crystallization, and enhances ingot quality. Additionally, this approach reduces polycrystalline silicon infiltration, increases the monocrystalline proportion of the ingot, and improves electrical properties and solar cell efficiency. This innovation provides a promising solution for scaling up high-quality cast mono-Si production at lower costs, boosting competitiveness in the photovoltaic market.