The reporter learned from Beijing graphene research institute that recently, Liu Zhongfan, academician of the Chinese Academy of Sciences and President of Peking University / Beijing graphene Research Institute, Liu Zhiqiang, researcher of the Institute of semiconductors of the Chinese Academy of Sciences, and Gao Peng, researcher of the school of physics of Peking University, have proposed a nano column assisted van der Waals epitaxy method, using metal organic chemical vapor deposition (MOCVD), For the first time in the world, continuous and flat quasi single crystal gallium nitride (GAN) films were successfully "heteroepitaxed" on glass substrates, and blue light emitting diodes (LEDs) were prepared. Relevant achievements were published in science progress, a subsidiary of science, on July 31.

The semiconductor industry is the bottom guarantee for the self-reliance of science and technology. Under the influence of novel coronavirus pneumonia, the III era is the leading semiconductor industry to develop in the global information age, 5G era and new crown pneumonia epidemic. For a long time, the original innovation ability of nitride core materials and devices in China is relatively weak, and the core patent technology is insufficient. At the same time, due to the lack of homogeneous substrates, nitride materials have been heteroepitaxy on sapphire, silicon, silicon carbide and other single crystal substrates by metal organic chemical vapor deposition (MOCVD). The size, cost, lattice mismatch, thermal mismatch and thermal conductivity of single crystal substrates limit the development of nitride materials. Therefore, getting rid of the limitations of traditional substrates is not only the bottleneck of nitride material preparation, but also the key to lead the development of advanced semiconductor industry through independent innovation.

The researchers solved this problem by skillfully using graphene. At the initial stage of growth, they used the lattice of graphene to guide the lattice arrangement of nitrides, and realized the epitaxy of high-quality nitrides on amorphous glass. Generally, nitrides grown on glass have a completely disordered polycrystalline structure. The lattice guiding effect of graphene makes the out of plane orientation of nitrides on the glass completely consistent, and the in-plane orientation is limited to three kinds from the usual random orientation, so as to obtain high-quality quasi single crystal films. They further grew a blue LED structure with an internal quantum efficiency of 48.7%. In addition, they made full use of the weak van der Waals force at the interface to mechanically peel the grown epitaxial structure and prepare flexible LED samples. It is reported that for large-scale industrial applications, Beijing graphene Research Institute has developed a series of graphene wafer preparation methods by using chemical vapor deposition on glass substrates, providing a solid foundation for the exploration of nitride revolutionary preparation technology.

Liu Zhongfan said that this achievement is a typical original breakthrough of "from 0 to 1", which provides a new idea for the industrial application of two-dimensional materials such as graphene. It is expected to develop a revolutionary preparation technology for nitrides, solve the bottleneck of advanced semiconductor development technology, and have important application prospects in the fields of new display and flexible electronics. At the same time, this technology reduces the dependence of nitrides on single crystal substrates through "heterogeneous epitaxy", which is of great significance to expand the selection range of semiconductor epitaxial substrates, enrich the concept of semiconductor heterogeneous epitaxy, and realize on-chip material assembly and heterogeneous integration in the post molar era.