The third generation semiconductor materials represented by GaN have significant advantages such as direct band gap, large band gap width, high breakdown field strength, high electron saturation drift rate, high thermal conductivity, etc. It has important application value in the fields of high frequency, high efficiency, high temperature, high power, high withstand voltage, radiation resistance, etc. It is expected to become the pioneer of China's semiconductor industry and technology to overtake at a bend, It has been written into the National "Fourteenth Five Year Plan" and the "Outline of Vision Goals for 2035", and is also the key development object of the Fourteenth Five Year Plan of Guangdong Province. In fact, in recent years, with the rapid development of new displays, 5G communications, the Internet of Things, new energy vehicles and other fields, the market scale of microwave RF devices, power electronic devices, lasers and Micro LED based on GaN materials has expanded dramatically. However, the epitaxial growth of large size and high-quality GaN core device materials is still the key factor limiting its high-end application. Based on this, the team will closely focus on stress regulation, dislocation and point defect suppression, surface/interface engineering, and energy band engineering of large mismatch heteroepitaxial materials, and explore new epitaxial growth technologies such as quasi van der Waals epitaxy, nitrogen polar GaN material epitaxy, to provide core material support for the research and development of high-performance optoelectronics and electronic devices of various nitride semiconductors.