Abstract: “How to break through the preparation theory and technology of large-size crystal materials” is one of the top ten frontier scientific questions released by China Association forScience and Technology in 2021, which revealing the crystal growth mechanism and breaking through the key growth technologies are the two trends of the development of large-size functional crystals. At the atomic or molecular scale, the crysttal growth can be described as a themal activation process with a barrier or an ultrafast growth of crystal without barrier, whiech is related to the specific system and growth direction. Based on the properties of interface, the smooth interface grow by the wray of step expansion, and the rough interface has no obvious solid-liquid stratification, and the growth can be completed bylocal atomic solidification. The advances of growth theory and technology for the large-size crystals in recent years have been summarized from three aspects: model, technology of growth and its application, and the application of molecular dynamics inn crystal growth. At present, there are many methods to grow large-size crystals,but the crystal quality is poor and performance is unstable. The reasons are that the existing technology do not take the micro-mechanism of crystal growth into consideratioln, and the relationship among crystal growth mechanisms and external factors such as temperature and flow rate are not clear. Using machine learning force field and molecular dynamics simulation method to establish solid-liquid interface and to ssimulate crystal growth would be an effective way to explore the micro-mechanism of crystal growth.

Key words: large-size crystal, synthetic crystal, crystal growth model, growth theory, solid-liquid interface