在定向凝固多晶硅铸锭生产过程中，由于带Si3N4涂层的石英坩埚壁与硅铸锭发生粘连、污染而导致大尺寸Si铸锭中一级品切出率过低，是该行业长期未解决的技术难题。这表明涂层材料体系和结构不尽合理，本质原因在于Si/Si3N4/SiO2三元体系高温界面反应机理不清楚。.针对以上问题，本课题旨在系统研究Si/Si3N4/SiO2三元体系高温界面反应机理。首先制备具有不同组成、结构的Si3N4多孔涂层，通过座滴实验系统研究Si熔体对涂层的润湿、渗透、反应等界面行为，建立Si熔体对Si3N4/SiO2体系的熔渗动力学；此后，提出新型结构涂层材料的设计原则，并制备出结构可调控的涂层材料，最终实现对反应、润湿等界面行为的预测和调控，从而使Si铸锭中一级品率大幅度提高。.通过课题研究，发展出一种反应、润湿等界面行为可控的Si3N4涂层新材料，为我国太阳能多晶硅铸锭产业中的关键新材料及其制备技术提供理论支撑。

A problem in the production of photovoltaic Si by directional solidification is the sticking of the Si ingots to the silica crucible walls, which often leads to contamination and cracking of Si ingots. To solve this problem, the microstructure of the Si3N4 coatings should be optimized and the interfacial reaction mechanism in the Si/Si3N4/SiO2 system requires to be clarified..This project proposes a comprehensive study on the interfacial reaction mechanism in the Si/Si3N4/SiO2 system. At first, Si3N4 porous coatings with different composition and microstructure will be prepared. Then, the reaction, wetting, and infiltration behavior of Si melt will be investigated by sessile drop method to establish the infiltration kinetics. Finally, a principle for microstructure design will be suggested and coatings with controlled microstructure will be prepared..After the execution of the project, Si3N4 coatings with novel microstructure and interfacial behaviors that can be manipulated will be developed, thus supporting the solar energy industry in both theory and practice.